Topkapa Palace is the old palace in Istanbul, close to St. Sophia Cathedral. Tickets are 40 lira, or you can buy a package of 85 lira, generic. The old palace is very large. It takes about two to three hours to visit it. There are many museums to visit. The scenery of the old palace is also very good. It is suitable for walking. Especially in the seaside part of the palace, it is very beautiful. It can overlook the Jinjiao Bay and the new urban area opposite the bridge. It's also a must-see place in Istanbul. It's really a good place to visit.