This bridge is named after the Leliegracht, which in turn is named after the Oude Leliestraat , which in turn is named after the house “In de Witte Lelye” on the Singel . The suffix sluice goes back to the Amsterdam designation for a stone bridge. Unlike elsewhere in the city, there is a former lock just a stone’s throw away , also called the Leliesluis (Lely Sluys). The contours of that lock are still visible in the Leliegracht.
Photos from the archive
1. It is difficult to let a boat pass under the Leliesluis (bridge 61). In the middle corner house Prinsengracht 245A, cinema annex theater, on the right the Leliegracht. Collectie Stadsarchief Amsterdam: oktober 1930
2. The Prinsengracht seen in a northerly direction towards the Leliesluis (Brug 61) 1900 ca.
3. In the foreground: Leliesluis (bridge 61) with left corner Leliegracht. In the background: Westermarkt with Westertoren. Alberts, Martin Stadsarchief Amsterdam: 21 december 2007
4. Aerial view to the west, with the Leliegracht with the Leliesluis (bridge 61) in front, the Westermarkt and the Bloemgracht (partly) on the left. In the middle the Jordaan with the Egelantiersgracht, at the top left the Marnixstraat and to the right the Westerstraat. Archief van de Dienst Ruimtelijke Ordening en rechtsvoorganger: augustus 1973
More at https://archief.amsterdam/beeldbank/?mode=gallery&q=leliesluis&page=1&record=3120f762-2774-5233-60cb-4221b65937ac&view=horizontal&reverse=0