A leisure centre is like a big playground for grown-ups that has lots of different things to do. There's a big swimming pool where you can splash around, go down water slides and jump off diving boards to make a big splash.
There is also a gym where adults can go and exercise their muscles by using machines and weights. There may also be fitness classes that are like dancing or stretching but are a little more challenging than playing around.
Some leisure centers have sports facilities like a big hall where you can play basketball or badminton. There may also be some outdoor space where you can play football, tennis, or other sports.
There are also things to do that don't require much physical activity, where people can sit down and relax. You can just read a book and chill out in a quiet area or in the lounge area with comfy chairs.
Everyone can visit leisure centers whether they are young or old, and you can have a lot of fun whilst being safe too!