Barquq Castle (Arabic: قلعة برقوق, romanized: Qalʿat Barqūq), also known as the Younis al-Nuruzi Caravansari or simply Khan Younis, was a Mamluk-era fortified mosque and caravanserai. It was one of the most important Mamluk strongholds in the region. The city of Khan Yunis in the Gaza Strip takes its name from this building, which is 20 kilometres (12 mi) from the Egypt–Gaza border. It lies along the historical road from Cairo to Damascus, known as the Via Maris. It was damaged by the Israeli army during the Gaza war.

An Arabic inscription above the entrance states that the building was constructed in 1387–1388 by Yunis al-Nawruzi [ar], a dawadar of the Mamluk Circassian sultan Barquq. Both Yunus and Barquq are named in three Arabic inscriptions above the building's main gateway, and the building's two common names – Barquq Castle and Khan Yunis – are thus thought to derive from their names. Others have claimed that the latter refers to the prophet Jonah (also Yunis in Arabic). The word castle in the name is a translation of the Arabic word qalat, meaning fortified building, whereas khan is another word for caravanserai and refers to its initial use as a place for travelling merchants.

It was built as a caravanserai to serve as a center in the middle of the road between Damascus and Cairo, the two largest cities in the Mamluk Sultanate, to protect merchant caravans, pilgrims and travellers. The khan also served as resting stop for couriers of the barid, the Mamluk postal network in Palestine and Syria.

During the 17th and 18th centuries the Ottomans assigned an Asappes garrison associated with the Cairo Citadel to guard the fortress.

It was visited in 1863 by French explorer Victor Guérin, who described it as follows:

[…] apart from the western facade and some parts of the perimeter wall, this castle is now very degraded and completely falls into ruin. It formed a large square, flanked, at its four angles, by a round half-turn. A mosque, still quite well preserved, bears the name of Jamia Sultan Barquq; it is decorated inside, and in particular the pulpit to preach or member, placed near the mihrab, with quite beautiful pieces of gray-white marble, coming, according to all appearances, from old buildings. The other materials that were used to build this mosque as well as the rest of the castle must also be partly antique; but they have been diminished. The inside of the fortress is currently occupied by very dilapidated private dwellings. It was once preceded by another larger enclosure, also flanked by towers, which is three-quarters demolished.

Gottlieb Schumacher visited it in 1886:

[…] the fine minaret and mosque, together with the ancient Khân building erected by Sultân Barkûk, built in the Arabic style of architecture, of sandstone and marble, with fair architectural details. The whole building has a length of 237 feet, and a width of 38 feet at the gate, and was flanked on each of its four corners by a round tower; a large wing added to the southern end is fallen. The "Khân" had two stories, the lower being the Khân itself, the upper evidently rooms for guests with the Jâma'. The main entrance facing west is spanned by a pointed arch, and in its bay a second gate with a segmental arch was constructed. The entrance is ornamented with lion figures, Kor'an citations and arabesques, above which on each side of the gate the name of "Sultan Barkûk" and a dedication to him is engraved. The entablature of the second story ended in a sort of ridge flower. To the right of the entrance a stairway leads to the Minaret, an octagon with an upper panel of later date, and to the left some passage must have led to the beautiful cupola spanned over the Jâma'... The cupola has a height of 24 feet, and is spanned over a room of 17 feet square; its layers run in concentrical rows, the stones being exactly worked; just the eastern half of this fine cupola is fallen. In the eastern wall a neat little pulpit of pure white marble and moresque work, with marble stairs leading up to it, is yet preserved.