The following buildings will become available once you meet the listed requirements after reaching level fifteen.

Building	Requirement	Effect
Aquarium	25 Golden Keys	20% population boost.
Astro-Twirl Rocket Ride	32 Golden Keys	30% population boost.
Bluebeard's Pirate Ship	13 Golden Keys	20% population boost.
Carousel	7 Golden Keys	10% population boost.
Crescent Shopping Mall	16 Golden Keys	20% population boost.
Lifeguard Tower	10 Golden Keys	10% population boost.
Lighthouse	15 Golden Keys	20% population boost.
Luxury Boat Marina	50 Golden Keys	30% population boost.
Merman Statue	20 Golden Keys	20% population boost.
Relaxing Beach	12 Golden Keys	20% population boost.
Sailorman's Pier	22 Golden Keys	30% population boost.
Surfer Beach	20,000 Simoleons	10% population boost.
Volleyball Courts	5 Golden Keys	10% population boost.
Water Park	18 Golden Keys	20% population boost.