Aqaba is the only seaside town in the Hashemite Kingdom.
My suggestion
If you want to swim, it's better to avoid the beaches in the center of town which are quite dirty. It's better to take a car or a taxi to go to one of the numerous well-developed beaches south of the town.
On the Road of the King, between Madaba and Petra, the imposing castle of Kerak stands proudly. Whether you're a history buff or just have a tourist's curiosity, you will no doubt be impressed by the feeling of power that the castle exudes; it's clear that this was once the stronghold of the 12th Century crusaders.