Gülhane Park was once part of the grounds of Topkapı Palace, accessible only to the royal court. These days crowds of locals come here to picnic under the many trees, promenade past the formally planted flowerbeds, and enjoy wonderful views of the Bosphorus, Sea of Marmara and Princes' Islands from the park's northeastern edge. The park is especially lovely during the İstanbul Tulip Festival, when thousands of tulips bloom.
Next to the southern entrance is the Alay Köşkü (Parade Kiosk), now open to the public as the Ahmet Hamdi Tanpınar Literature Museum Library. Inside, next to the western walls is the İstanbul Museum of the History of Science & Technology in Islam.
Across the street from the main park entrance and 100m downhill from the park's main gate is an outrageously curvaceous rococo gate leading into the precincts of what was once the grand vizierate, or Ottoman prime ministry, known in the West as the Sublime Porte thanks to this flamboyant entrance. Today the buildings beyond the gate hold various offices of the İstanbul provincial government (the Vilayetler).