For Whom The Web Rocks
Puerto Rico - Rules - Fortress

The owner of the occupied fortress earns, at game end, one additional victory point for every three colonists on his player board.

Example: At game end, the owner of the occupied fortress has filled a total of 20 colonists on his plantations, quarries and buildings, and in San Juan: he earns an additional 6 VP.

Costs 10 doubloons
4 victory points

1 victory point for every 3 colonists
(game end)