The Istanbul Museum Card is a discount card that allows visitors to Istanbul to access many of the city's museums and cultural attractions at a discounted rate. 

The card is valid for specific days (typically three, seven, or 10) and can be used at participating museums and cultural sites.

The Istanbul Museum Card offers discounts on admission to many of Istanbul's most famous museums, including the Hagia Sophia, the Topkapi Palace, the Istanbul Archaeological Museums, the Museum of Turkish and Islamic Arts, the Istanbul Modern, and many others. It also includes discounts on public transportation and other services.

The Istanbul Museum Card is a convenient and cost-effective way for visitors to explore the city's cultural offerings and can be purchased online or at participating museums. It is a good option for anyone planning to visit multiple museums in Istanbul.