The Hall is located on the S side of Front Quadrangle and is one of Merton's earliest buildings, cited in a document of 1277. E of the hall is a gateway to Fellow's Quadrangle. On the W side, the hall is connected to the Chapel sacristy by a small, recessed archway ca. 1510--20, built under the Warden Richard Rawlyns.

From drawings done by Agas (1578) and Loggan (1675), the original hall appears to have been a plain stone structure, with 2 louvres on the roof, and 3 large, transomed windows on both the N and S side. The E and W walls are probably original, and thus the original hall was likely of the same dimensions.

The transomed, 2-light windows with pointed trefoiled heads and handsome stone window seats have apparently been recreated exactly by Scott in the 19th c. (Pevsner, <i> Oxfordshire</i> 159). Scott also gave the hall its oak roof. Since then, very few changes have been made. The hall's vaulted undercroft was built in the 19th c.