Abydos is one of the great ancient sites of Upper Egypt, but it has a very different rhythm from Luxor. The buses are fewer, the village is quieter, and the monuments sit in desert light beside cultivated fields. For ancient Egyptians this was sacred ground: a royal cemetery, a pilgrimage centre of Osiris, and a place where kings linked themselves to the oldest dynasties.
The reason to come is the Temple of Seti I, a superbly preserved New Kingdom temple with some of the finest relief carving in Egypt. Behind it is the strange, partly sunken Osireion, while the wider landscape includes the early royal cemetery of Umm el-Qa'ab and the massive mudbrick enclosure of Shunet El Zebib.
Abydos is usually visited as a long day trip from Luxor, often paired with Dendara. That makes for a full day, but it is one of the best temple excursions in Egypt if you care about history and want a break from the crowds around Karnak and the Valley of the Kings.