Built around 1400, the Oostpoort is Delft's last surviving medieval city gate — all the other gates were torn down when the old town walls were demolished in the 19th century. The twin towers in Brick Gothic style stand at the eastern approach to the old city, their reflections mirrored in the canal below. It is a remarkably photogenic structure, especially in the morning when the light comes from the east.
The gate is not open to the public inside, but the exterior is freely accessible. The best view is from the small bridge over the canal looking back toward the towers. A short walk from the Markt via the Koornmarkt canal. Often less crowded than the central sights, and worth the 10-minute detour.