The Great Wall's main gate as it snaked down the mountains towards the sea, the First Pass served as Shanhaiguan's east gate and principal watchtower. Two storeys tall, with double eaves and 68 arrow-slit windows, it's a towering 13.7m high, with an enceinte extending east.
The ¥40 ticket allows you to walk along the wall, south to the Jingbian Watchtower (靖边楼; Jìngbiān Lóu), which also serves as an entrance for the First Pass. You can also walk a complete circuit of the town walls (¥120). A different combination ticket (¥50) also gets you into the Wang Family Courtyard as well as the renovated Drum and Bell Tower (钟鼓; Zhōng Gǔ) in the centre of the old town.