The Kuusistonlahti Natura area is comprised of shallow, reed-filled saltwater bays at both ends of the narrow strait between the islands of Kuusisto and Lyhtyholma, which have practically grown together as a result of the upthrust of the land masses. Altogether, the area of this Natura 2000 site totals 351 hectares. The former strait between the islands of Kuusisto and Lyhtyholma is known as the Kuusistonlahti bay area. The area consists of two shallow bays: Torpansuntti in the southwest, with abundant reed vegetation, and Fiskarinsuntti (or the actual Kuusistonlahti) in the northwest. Between these two bays, there is an extensive marsh or shoal area, a portion of which is still quite wet. Amidst this area, there is an embankment road leading to Lyhtyholma. Kuusistonlahti bay is mainly open water, surrounded by reeds.
Bearded Tit, Gadwall, Marsh Harrier, Red-backed Shrike, White-tailed Eagle, Osprey, Ruff, Common Redshank, Great Bittern and Common Greenshank are all rather easy here, depending on the year.
25 minutes drive from Turku. From road number 110, turn to Saaristotie road and drive until you see Tammisto Center on your left. Turn to the left onto Linnanrauniontie road, and continue toward the castle ruins. About 1.5 kilometres before the castle ruins, take a turn to the right, to Lyhdyntie road, and drive to the southern bird watching tower of Kuusisto. Parking lot is 50 m from the tower.