Two identical stones on the north and south shores of Lantau Island mark the points at which the sea boundary (Pre-1997) with China touches the Island. The stones are granite, pointed on top, and standing on stone bases. A carved inscription on one of the faces of each base states that the stones were fixed in position by Lieutenant-Commander F.M. Leake, R.N. and officers of H.M.S. Bramble in 1902 in the longitude 113°52'0". The opposite face bears a corresponding inscription in Chinese. Both stones are marked as obelisks on ordnance maps.
The text differs slightly on the two stones. The full text on the Southern Obelisk:
1902
This stone is in longitude
113°52'0" fixed by Lieut and
Comdr F.M. Leake, R.N. and the
officers of H.M.S. "Bramble".
From here the boundary
follows the western shore of
Lantao Island until it meets a
similar stone erected in the
same longitude on the north
side of the island southward.
The boundary extends to the
parallel of 22°9'0".
This stone is placed 200
feet above H.W. mark for the
purpose of protecting it from
possible inroads of the sea.
Source: In Search of the Past: A Guide to the Antiquities of Hong Kong and own notes. See Lantau North Obelisk here The obelisk marking the eastern longitude of Hong Kong can be read here