Lago Ercina

Speleogroup  title


Site list (GPS fixes) Walks (GPS tracks)  Video clips Panoramas

Coordinates used

Electronic projects:

 Bat detector
 Lamp tests
 µ-controlled lamp
 SEPIC-based lamp
 ISP isolators
 Making SMT boards

Expedition logs:

 1973, 1974, 1975,
 1976, 1977, 1979,
 1982, 1983, 1985,
 1986, 1987, 1988,
 1989, 2000, 2001,
 2002, 2003, 2004,
 2005, 2006, 2007,
 2008, 2009, 2010,
 2011, 2012, 2013,
 2014, 2015, 2016,
 2017, 2018, 2019
 Mexico, New England


 The Battle of
 El Mazuco

Sites of Speleogroup interest

Locations in the table below are usually at a point closest to the site where a GPS fix was possible; this point is sometimes ten or more metres from the site. Locations are sorted West→East. Click on a coordinate to see that coordinate on Google Maps.

The full list is also available in a single GPX file, generated from this page.

The first column (T) describes the ‘type’ of the site (experimental; may change) – this also sets the icon assigned to the site in the single GPX file:

B – historical/speleological Bar

C – cave (enterable)

K – karst feature (depressions, etc.)

P – point of interest (waypoint, parking places, rock shelter, etc.)

R – resurgence (no cave)

S – sink (no cave).

Coordinates are in °,′,″ (using the WGS84 datum) and UTM eastings and northings. To convert coordinates to the European 1950 datum as used on most Spanish maps (including the 1:25,000 ‘blue series’), add 4.1″ to N and subtract 4.8″ from W (an adjustment of ~160m). For more details on this and the grid systems used on the Spanish maps of the area, see Coordinate systems.

Altitudes shown with ‘?’ are suspect – uncalibrated altimeter or GPS.
T Coordinates Site
C N43°20'14" W5°54'29"
30T 264.28 4802.37
Cueva de las Caldas
S N43°17'56" W5°55'40"
30T 262.51 4798.16
Sumidoiru (La Mortera)
S N43°30'32" W5°29'36"
30T 298.56 4820.56
El Sumidoriu sink
C N43°13'15" W5°26'49"
30T 301.38 4788.45
Tarna Hydroelectric plant cave
C N43°10'41" W5°21'41"
30T 308.19 4783.50
Devoyu resurgence
C N43°10'41" W5°21'27"
30T 308.51 4783.49
Devoyu sink
C N43°26'47" W5°11'49"
30T 322.35 4812.93
Cueva del Sumidero
C N43°27'24" W5°06'23"
30T 329.70 4813.88
Cueva de les Pedroses
C N43°27'23" W5°06'22"
30T 329.71 4813.85
Cueva de les Pedroses sink (cave?)
C N43°20'12" W5°06'04"
30T 329.79 4800.55
Cueva La Huelga
C N43°26'12" W5°04'27"
30T 332.25 4811.62
Cuevona North Entrance
C N43°26'03" W5°04'20"
30T 332.39 4811.32
Cuevona South Entrance
C N43°27'39" W5°04'08"
30T 332.75 4814.28
Cueva del Tenis
C N43°27'39" W5°04'06"
30T 332.68 4814.07
Cueva del Tenis exit
C N43°18'29" W5°03'20"
30T 333.40 4797.28
Santa Cueva, in Covadonga
C N43°18'00" W5°03'14"
30T 333.51 4796.39
Cueva Orandi
R N43°18'13" W5°03'01"
30T 333.82 4796.78
Gueyu Reinazo resurgence
P N43°25'22" W5°02'53"
30T 334.32 4810.01
Santianes Molín de Arriba
K N43°17'56" W5°02'40"
30T 334.17 4796.03
Trumbio lower entrance?
K N43°23'56" W5°02'05"
30T 335.34 4807.33
La Mujerina area big depression
C N43°25'46" W5°02'15"
30T 335.20 4810.73
K N43°25'28" W5°01'58"
30T 335.56 4810.17
Tinganón feeder’ (337m)
C N43°17'43" W5°01'56"
30T 335.26 4795.82
P N43°26'02" W5°01'08"
30T 336.71 4811.19
The ‘Polígono hole’, 250m above Polígono Guadamia
P N43°26'12" W5°00'59"
30T 336.91 4811.49
Below possible Cueva Negra old resurgence
C N43°25'21" W5°00'27"
30T 337.60 4809.90
Cueva Negra (455m)
R N43°26'02" W5°00'18"
30T 337.84 4811.16
Madre del Río
B N43°16'19" W4°58'57"
30T 339.22 4793.13
Lago Ercina Bar María Rosa
P N43°16'18" W4°58'57"
30T 339.23 4793.10
Lago Ercina carpark
K N43°15'36" W4°58'44"
30T 339.49 4791.80
Forcau route possible caves at +1235m
C N43°15'27" W4°58'28"
30T 339.85 4791.51
Forcau route vertical cave at +1306m
K N43°16'51" W4°58'43"
30T 339.57 4794.11
Lago Ercina cow-shelters
K N43°27'40" W4°58'24"
30T 340.46 4814.11
Pozo de las Grallas, Bufones de Pría (41m)
P N43°14'57" W4°57'59"
30T 340.47 4790.57
Forcau col
C N43°14'52" W4°58'03"
30T 340.39 4790.42
Pozu de Vega El Forcau, +1480m, reconfirmed 2011
S N43°24'52" W4°57'55"
30T 341.00 4808.94
Llamigo sink
C N43°19'32" W4°57'27"
30T 341.40 4799.05
El Peruyal, near Benia
K N43°19'52" W4°56'39"
30T 342.49 4799.64
Avín depression
S N43°21'53" W4°56'38"
30T 342.59 4803.37
Vega de Hibeo sink
P N43°19'13" W4°55'07"
30T 344.42 4798.17
Minas de Alda
C N43°19'31" W4°55'07"
30T 344.55 4798.93
Cueva Tayada (Cueva Alda), 450m?
C N43°21'38" W4°54'53"
30T 344.96 4802.85
“Cueva Geoffo” (Cosagra), 190m
S N43°24'53" W4°54'43"
30T 345.32 4808.85
Vizcaina/L’Acebal sink, 119m?
C N43°20'03" W4°54'12"
30T 345.81 4799.89
Cueva Dobros (Depression N of Ortiguero)
B N43°26'33" W4°54'16"
30T 346.00 4811.93
Bar La Cueva, Villahormes
R N43°12'47" W4°54'09"
30T 345.57 4786.44
Resurgences at Caín, 473m?
P N43°24'37" W4°54'10"
30T 346.05 4808.34
Rales System car parking for Molino
K N43°23'14" W4°53'50"
30T 346.43 4805.78
Rotella large depression cave
P N43°24'40" W4°53'45"
30T 346.60 4808.43
Saddle between Rales and Fuentica
C N43°24'39" W4°53'44"
30T 346.64 4808.39
Rales System
K N43°26'51" W4°53'10"
30T 347.50 4812.46
Playa Gulpiyuri
C N43°19'04" W4°52'30"
30T 348.07 4798.02
Flea cave, +287m
C N43°22'44" W4°51'58"
30T 348.94 4804.80
Caldueñín, 140 m
P N43°20'57" W4°51'26"
30T 349.59 4801.47
Tebrandi trailhead, ~770m
C N43°22'44" W4°51'20"
30T 349.79 4804.77
Pozo de Fresno »
P N43°23'00" W4°51'11"
30T 350.01 4805.26
El Mazuco, Ermita del Santo Ángel (confirmed ±0.5″ over several years and devices)
P N43°22'42" W4°51'05"
30T 350.12 4804.70
‘Car paddock’ parking for Boriza/Fresno
R N43°24'43" W4°50'54"
30T 350.46 4808.43
Resurgence below Green Sink
P N43°22'40" W4°50'35"
30T 350.80 4804.64
Old resurgence? above Boriza
P N43°22'39" W4°50'35"
30T 350.80 4804.58
Hole next to track immediately above Boriza
P N43°22'38" W4°50'35"
30T 350.81 4804.56
Boriza (track above and to S.)
R N43°22'43" W4°50'36"
30T 350.68 4804.50
Boriza resurgences 2019
S N43°22'40" W4°50'27"
30T 350.99 4804.62
Flood sink above Boriza
K N43°22'38" W4°50'20"
30T 351.13 4804.56
Boriza stream audible through rocks
C N43°23'56" W4°50'18"
30T 351.24 4806.96
Green Sink cave (above and to S. of sink)
R N43°22'29" W4°50'02"
30T 351.54 4804.27
Ojo del Río Bolugas
C N43°22'31" W4°49'58"
30T 351.64 4804.35
Cueva a Sul
C N43°22'25" W4°49'58"
30T 351.63 4804.14
Cueva de Collau Rubiera
P N43°22'51" W4°49'38"
30T 352.10 4804.94
End of the road S. of Alto de la Tornería
P N43°22'44" W4°49'22"
30T 352.46 4804.73
Rafa’s Cabaña
R N43°22'14" W4°47'40"
30T 354.73 4803.74
Spring at west end of Viango
C N43°22'10" W4°47'12"
30T 355.36 4803.60
Cueva de la Yosa del Viango
P N43°10'07" W4°47'09"
30T 354.95 4781.29
Refugio de Áliva (1666m)
K N43°22'28" W4°46'41"
30T 356.06 4804.14
Dry stream valley, NE Viango
K N43°12'16" W4°46'27"
30T 355.98 4785.25
‘Cow shelter’ caves, nr. road to Áliva
B N43°24'05" W4°46'20"
30T 356.60 4807.12
Bar La Roxia at La Pareda
C N43°24'00" W4°45'56"
30T 357.14 4806.96
Cueva Bolado (Herrería)
C N43°22'22" W4°44'13"
30T 359.39 4803.89
Fuente Grande, near Viango
C N43°14'25" W4°44'09"
30T 359.17 4789.17
Possible cave near Sotres TV mast
K N43°14'24" W4°44'16"
30T 358.91 4788.95
Arch near Sotres TV march – guess from SatView
K N43°14'22" W4°44'14"
30T 358.96 4788.87
Arch near Sotres TV march – reckoned from photo bearings
S N43°14'06" W4°43'27"
30T 360.11 4788.56
Sink 3km E of Sotres (1277m?)
C N43°14'09" W4°43'25"
30T 360.16 4788.65
Shaft 3km E of Sotres (1276m?)
C N43°22'35" W4°43'18"
30T 360.64 4804.26
El Cuevón de Pruneda (Purón cave)
K N43°22'07" W4°42'53"
30T 361.18 4803.39
Holly depression above Las Conchas
K N43°14'21" W4°42'45"
30T 361.07 4789.01
Sotres crossroads depression
C N43°15'16" W4°42'14"
30T 361.81 4790.69
Cueva de la Marniosa
R N43°22'18" W4°41'49"
30T 362.64 4803.68
Nacimiento de Río Purón
R N43°15'19" W4°41'47"
30T 362.41 4790.77
Valle de Sobra resurgence and cheese cave (849m?)
C N43°15'19" W4°41'44"
30T 362.48 4790.77
Valle de Sobra abandoned cheese cave (15m E)
C N43°14'47" W4°40'29"
30T 364.15 4789.75
Cueva del Nacimiento/Agua
P N43°19'39" W4°40'22"
30T 364.49 4798.74
‘Cobalt’ mines, Río Cares
C N43°16'27" W4°40'19"
30T 364.44 4792.83
Cueva de Los Jarres, San Esteban
K N43°21'44" W4°40'03"
30T 364.99 4802.60
La Borbolla top depression
K N43°21'46" W4°39'58"
30T 365.11 4802.66
La Borbolla middle depression (El Jorcón)
K N43°21'47" W4°39'12"
30T 366.14 4802.67
La Borbolla lower depression
C N43°19'57" W4°38'46"
30T 366.65 4799.26
Cueva Llonín
C N43°14'21" W4°38'37"
30T 366.65 4788.90
Cueva la Sotorraña (as shown on survey/board)
C N43°23'39" W4°38'33"
30T 367.09 4806.11
Pendules shelters
P N43°14'49" W4°38'29"
30T 366.86 4789.75
Bejes Puente Pumpedrei #1
P N43°14'47" W4°38'31"
30T 366.82 4789.68
Bejes Puente Pumpedrei #2
C N43°16'28" W4°38'06"
30T 367.44 4792.80
Pozo del Infierno (310m)
P N43°21'56" W4°38'05"
30T 367.66 4802.92
La Borbolla village
R N43°21'50" W4°38'02"
30T 367.73 4802.73
La Borbolla resurgence
C N43°16'02" W4°38'01"
30T 367.54 4791.98
Urdón cave (estimate; GPS impossible)
C N43°23'42" W4°36'37"
30T 369.71 4806.16
Cobigeru 2 muddy cave
C N43°23'41" W4°36'36"
30T 369.72 4806.10
Cobigeru 1 resurgence
C N43°23'47" W4°36'35"
30T 369.76 4806.29
Cobigeru 3 – sea cave
R N43°18'35" W4°36'31"
30T 369.66 4796.68
Vauclusian spring (Deva gorge, between Estragüeña and Puentelles)
R N43°15'09" W4°36'30"
30T 369.55 4790.32
La Hermida hot spring
R N43°17'59" W4°36'24"
30T 369.79 4795.56
Fuente de Estragüeña, 110m
C N43°23'23" W4°34'50"
30T 372.00 4805.30
Cueva Mazacuíos, La Franca
C N43°18'06" W4°35'39"
30T 370.81 4795.76
Goat Cave through trip
C N43°18'06" W4°35'37"
30T 370.84 4795.77
Crow Cave with pitch
K N43°18'04" W4°35'36"
30T 370.88 4795.71
“El Arco”
C N43°18'03" W4°35'35"
30T 370.88 4795.67
Cueva del Arco (480m)
C N43°12'17" W4°35'36"
30T 370.66 4785.00
Cueva de Fair Share (BUSS 1973; 215m)
C N43°18'50" W4°35'15"
30T 371.37 4797.10
Cueva La Redonda (Suarias) (161m)
S N43°18'01" W4°34'53"
30T 371.84 4795.59
Sink in boulders in big depression above Suarias (Corvera)
K N43°20'59" W4°34'46"
30T 372.10 4801.07
Andinas westernmost (highest) depression
K N43°14'08" W4°34'31"
30T 372.21 4788.39
Riega de Cicera ‘pothole in the wall’
R N43°17'54" W4°34'22"
30T 372.53 4795.37
Suarias Corvera resurgence
C N43°18'08" W4°34'18"
30T 372.63 4795.78
Cabañuca, 305m
R N43°18'20" W4°34'16"
30T 372.69 4796.15
Cabañuca resurgence, 208m?
C N43°19'53" W4°33'34"
30T 373.68 4799.01
Cueva La Loja
P N43°19'18" W4°33'14"
30T 374.10 4797.93
Track to 1973 cave(?), near Morodio (2015 »)
S N43°19'56" W4°33'30"
30T 373.78 4799.10
Andinas bottom sink
K N43°19'42" W4°31'16"
30T 376.78 4798.61
Canto Grande depressions, Cabanzón
C N43°19'04" W4°30'42"
30T 377.53 4797.44
Cueva de Casamaría (2015 »)
P N43°17'00" W4°30'23"
30T 377.88 4793.59
Saddle above Cororigo resurgence (2015 »)
P N43°20'12" W4°29'50"
30T 378.74 4799.49
Cofría resurgence rift parking (nr. Sobanejo)
R N43°20'22" W4°29'21"
30T 379.40 4799.81
Cofría resurgence rift 2009 & 2010
C N43°18'27" W4°29'17"
30T 379.41 4796.24
Cueva Las Brujas (~170m)
C N43°20'25" W4°29'07"
30T 379.72 4799.87
Cofría sinks (Regato Mata del Tocial)
S N43°16'49" W4°29'13"
30T 379.46 4793.22
Cueva Toyu river sink
K N43°16'53" W4°29'13"
30T 379.47 4793.35
Cueva Toyu ‘nettle feature’
C N43°16'55" W4°29'09"
30T 379.54 4793.41
Cueva Toyu NW ‘torca’ entrance
P N43°16'56" W4°29'08"
30T 379.57 4793.42
Cueva Toyu old barn NE corner (203m)
C N43°16'54" W4°29'04"
30T 379.66 4793.39
Cueva Toyu NE ‘Roza’ entrance
C N43°16'59" W4°29'03"
30T 379.70 4793.53
Cueva Rozada, near Cueva Toyu
P N43°16'55" W4°28'59"
30T 379.77 4793.41
Cueva Toyu resurgence
C N43°16'44" W4°28'58"
30T 379.79 4793.07
Cueva de los Marranos »
C N43°16'44" W4°28'57"
30T 379.82 4793.07
Cave 68
C N43°20'29" W4°14'11"
30T 399.88 4799.68
Cobijón cave
P N43°20'27" W4°14'11"
30T 399.90 4799.62
Cobijón – river, close to cave
S N43°04'44" W4°14'09"
30T 399.52 4770.52
Sink at at Venta de Tajahierro
K N43°20'20" W4°12'46"
30T 401.81 4799.38
Bustablado depression cliff
R N43°11'34" W3°35'02"
30T 452.56 4782.38
Nacimiento del Gándara
C N43°12'23" W3°34'21"
30T 453.50 4783.89
Torca del Mortero de Astrana
C N43°14'02" W3°34'00"
30T 454.00 4786.95
Garma Ciega
K N43°15'18" W3°33'12"
30T 455.09 4789.27
Hoyo Masallo
S N43°20'36" W3°42'20"
30T 442.81 4799.18
El Coladillo sink (close to La Cavada, SSE of Solares)
R N43°15'05" W3°36'23"
30T 450.89 4789.12
Puente Cubera resurgence, Asón (~200m)
C N43°20'22" W3°22'09"
30T 470.18 4798.78
Cueva Los Tocinos
C N43°20'14" W3°21'55"
30T 470.49 4798.54
10m SE of small cave above Hoya Mena sink
S N43°20'15" W3°21'54"
30T 470.51 4798.56
Hoya Mena sink
S N43°23'58" W3°21'31"
30T 471.08 4805.46
Hazas sink
R N43°23'47" W3°19'44"
30T 473.47 4805.11
Oriñón resurgence
C N43°21'41" W3°16'37"
30T 477.67 4801.20
Cubilla (192m)
P N43°21'45" W3°16'34"
30T 477.74 4801.32
Parking above Cubilla
C N43°21'34" W3°15'22"
30T 479.36 4800.97
Cueva Lastrilla (98m?)
P N43°21'37" W3°14'52"
30T 480.03 4801.06
Turn-off to Cueva Lastrilla
P N43°06'56" W2°40'05"
30T 527.12 4773.91
Parque Natural de Urkiola
C N43°07'16" W2°43'31"
30T 522.46 4774.51
La Cueva de Balzola (308m)
C N42°59'25" W2°25'15"
30T 547.33 4760.11
Cueva Gesaltza

 †  Location estimated from map or other source (all other coordinates are GPS readings).

Expeditions to the Picos de Europa and elsewhere since 1973.
Please e-mail Mike Cowlishaw ( or Bill Collis (
if you have any corrections, suggestions, etc.   See also the SpeleoTrove speleology section ».
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This page was last edited on 2020-01-02 by mfc.