This seems to me to be one of those cases where the original word should be maintained and some sort of translation or explanation added in brackets. "Almogaren" is a local guanche word derived from Berber, and basically means a religious site or sanctuary. Archaeologists refer to these sites in the Canaries with the original term "almogaren" (without the accent).

Various English equivalents can be found, but I think "sanctuary" probably covers it best.

"Un Almogarén se caracteriza por la presencia de hoyos excavados en el suelo, llamados cazoletas. La palabra de origen beréber significa en lengua aborigen , casa de oración o santuario. Se cree que dichos lugares sirvieron para la realización de rituales de fecundación, para invocar la lluvia, ahuyentar enfermedades, curaciones . Se ofrecía a los dioses sangre de animales, leche, manteca para conseguir el favor de estos."
http://www.infonortedigital.com/portada/component/content/ar...


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Note added at 1 hr (2013-07-07 11:03:43 GMT)
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"Dr Pritchard (vol. ii p. 36) has given the following vocabulary of the Canarian languages, in order to prove their resemblance to the Berber or Shuluh [...]
English........................Berber or Shuluh.................Guanche
5. Temple.......................Talmogaren.....................Almogaren"
The Journal of the Royal Geographical Society, Volume 11 (1841), p. 177
http://books.google.es/books?id=iSY7AQAAIAAJ&pg=PA177&lpg=PA...

If the following is reliable, it would perhaps be better to say "sanctuary or place for sacrifices":

"Ancient Temple in Canary Isles

sanctuary of pre-hispanic inhabitants with very big main cave (temple), Tagoror ( gathering place), Almogaren (place for sacrifices) and further caves arranged as a village [..]
On the top of the hill is situated the so called Almogaren - a place for sacrifices."
http://www.megalithic.co.uk/article.php?sid=20274

" “almogaren”, a place to worship the gods of nature"
http://telde.es/opencms/export/sites/telde/portal/ayuntamien...


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Note added at 1 hr (2013-07-07 11:08:59 GMT)
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The point about sacrifices is mentioned in my first source too: "se ofrecía a los dioses sangre de animales". It looks to me as though the almogaren is a specific part of the sanctuary, where they did the sacrifices, with all the religious significance that involves (prayer, worship etc.). So maybe "place for sacrifices" alone would be best. It makes you wonder whether the "cazoletas" (cup marks, as I suggested in the other question) were for containing the blood.