Grendeltor, Medieval water gate at Limmat River, Zürich, Switzerland

The Grendeltor was a medieval water gate positioned at the northern end of the current Bellevue area, regulating ship movement between Lake Zürich and the Limmat River. The structure featured a spiked barrier beam that operated with the water current each morning to manage traffic flow.

Built around the mid-15th century, the gate likely incorporated lessons from the "Seekrieg" of the Old Zürich War (1436/50). A 1657 addition was the pentagonal ravelin "Kratz", today's Bauschänzli. The palisades were removed in 1834 and the gate demolished in 1836 under pressure from rural residents demanding free access to the city market.

The gate served as a checkpoint where officials collected fees from passing boats using a rope and bucket system. This daily routine shaped how merchant vessels operated on the waterway and underscored the importance of water traffic to the city.

The former location lies at the start of Utoquai, between number 2a and Limmatquai 6 in central Zürich. The spot is easily accessible on foot and offers a clear view of the waterfront where the gate once stood.

The gate's guard lowered a small kettle on a rope so arriving boats could drop their toll inside before passing. The gate also carried the city's double shield with a black two-headed imperial eagle on a yellow ground, painted beside the pointed arch.