The temple was built approximately 2200 years ago to honor the gods Amon and Isis. Constructed in the Nubian town of Debod (thus its name), it was later enlarged and redecorated by the Ptolemanic pharaohs and the Roman emperors.
Rebuilt on the site of a former Montana army barracks, it was opened to the public in 1972.
I found the temple and then waited and waited for it to open. 10:00 came and left. I checked my guidebook, and sure enough, it was a Spanish holiday.