Caparra preserves the remains of the first Spanish settlement on Puerto Rico, founded by Juan Ponce de Leon before the colonial capital moved to the more defensible islet of Old San Juan. What survives is fragmentary, but the foundations matter: this is where the early colonial experiment briefly tried to take root inland before geography won the argument.
The small museum helps make sense of the low stone walls and excavated traces outside. It is not as visually dramatic as the forts in Old San Juan, but it fills in an earlier chapter of the island's history and is worth the detour for travellers interested in archaeology and the first decades of Spanish rule in the Caribbean.