Valle San Bartolomeo, known to the Slovenes as Zaliv Sveti Jernej, is entered between Debeli rtič (45°35′N 13°42′E) and Punta Sottile, about 1 mile NE, at the head of the promontory separating Koprski Zaliv from Baia di Muggia. The bay is protected by high land, the slopes of which fall steeply into the sea at Debeli rtič. The bay served as the former quarantine anchorage for Trieste. Lazzaretto Nuovo, the former quarantine building stands near the centre of the E side of the bay. The border between Slovenia and Italy lies about 0. 4 miles S of Lazzaretto Nuovo. Good anchorage is afforded to vessels in a Bora W of Lazzaretto Nuovo in about 15 m, mud, good holding. During W winds this anchorage may become dangerous, and care is necessary to avoid the wreck previously described. The S part of the bay affords moderate anchorage for small vessels during SW winds.