Vialand is one of the two(so far) theme parks in Istanbul. It’s located not far to the center even though getting there with public transport is not that easy. But the good news is that they have regular shuttle vans from various locations od Istanbul directly to the park. This year(2016) prices have gone up almost by 90% compared to last year, but it’s still a nice park for everyone between 7 – 70 of age. I definately suggest you the free fall from the tower and the high speed roller coaster if you like the adrenaline. There are many other games and attractions of course. There are several restaurants and cafeterias inside so you don’t starve while you’re spending hours in here. There is a shopping mall and a hotel next door.