Ancient Building on a Hill Over Athens
Puzzle 19 of Day of the Dead Hard Pack
Question is: Ancient Building on a Hill Over Athens
and the answer is: ACROPOLIS
Word Meaning:
ACROPOLIS — A promontory (usually fortified with a citadel) forming the hub of many Grecian cities, and around which many were built for defensive purposes before and during the classical period; compare Acropolis.
Definitions from Wiktionary.