Now trapped between the British-built Aswan dam and the High Dam 6km (3 3/4 miles) upstream, the stunning Ptolemaic monuments on Philae Island were already being flooded regularly well before they were moved by UNESCO in the 1970s to a site on nearby Agilkia Island, 20m (66 ft.) higher than their original location. They are a must-see for visitors to Upper Egypt.
Temple of Isis -- This is the largest structure on the island, covering about a quarter of the available space on the island. The boat dock is by the Hall of Nectambo, and you pass a colonnade (a Roman addition to the temple) on your way to enter through the Gate of Ptolemy II. I particularly like the forecourt of this temple, with its densely worked columns and scenes of offering incised into the massive pylon that separates it from the hypostyle hall inside.
Temple of Hathor -- Though unfinished, the Temple of Hathor on the eastern side of the island is worth a look for the reliefs of musical entertainment that include Bes, the dwarf god of childbirth, playing a harp.
Kiosk of Trajan -- This is not a kiosk in the sense of a small structure, but rather a massive structure on the riverbank illustrated with scenes of the Emperor Trajan making offerings to Isis.
The best way to get to Philae is on your own, rather than with a crowd of other visitors who will set the pace for you. Take a taxi to Shellal, which is close to the Aswan Dam (the old one), and negotiate with a boatman at the dock. Expect to pay around LE50 to LE70 ($9.10-$13/£4.60-£6.50) for the taxi and another LE40 to LE50 ($7.25-$9.10/£3.70-£4.60) for the return trip by boat.