İstanbul University and its Mathematics Department are at the heart of historical İstanbul and there are many hotels and restaurants within walking distance, for example, in Sultanahmet district nearby, which is also easy to reach by various kinds of transport. Participants are expected to make their own hotel reservations using any online reservation service. Just in case, the workshop venue is at the Vezneciler station on the subway line M2. Here are a few reasonably priced and reliable university guest houses or teachers lodges (the web sites of the last two unfortunately only in Turkish, but with e-mail addresses and telephone numbers.
Anadolu University Aksaray Guest House
Cankurtaran Teachers Lodge
Beyoğlu Teachers Lodge

İstanbul has frequent connections with all major cities in the world via all major airlines. You can use its hub the new İstanbul Airport to arrive, which is on the same (European) side of the city as the workshop venue. Participants are expected to travel to their hotels or the workshop site from the airport, say, using the bus service. The closest arrival point of the buses in the city is Sultanahmet. If you use Sabiha Gökçen Airport on the other (Asian) side of the city, which is a less crowded airport for low-cost airlines, the means of reaching Sultanahmet is explained here. More easily, you can take the HavaBus shuttle mentioned there to Taksim, then take the subway from Taksim to the Vezneciler station, and then walk.

On the we page Network Maps, you can find maps for all the rail systems of İstanbul.

Visit the web site of Ministry of Foreign Affairs of Turkey for up-to-date information on visa requirements for foreign nationals planning to visit Turkey.