Alte Messe Leipzig, Messehalle 12, Exhibition hall architecture in Leipzig, Germany.

Messehalle 12, the former Achilleion, is a steel-framed exhibition hall on Leipzig's old trade-fair grounds. Its 81.5-metre-wide, 192-metre-long complex combined a stone-clad portico by Oskar Pusch with a three-aisled hall by Carl Krämer, whose riveted steel central nave had a barrel vault for displaying large machines.

The hall was built from 1923 to 1924 as an exhibition hall for the German Machine Tool Manufacturers' Association, on the old Leipzig fairgrounds used since the 1913 International Building Trade Exhibition. From 1927 it also served as the Achilleion sports palace for 8,000 spectators. Heavily damaged in World War II, it reopened in 1950 as the Soviet pavilion and was renumbered Hall 12 in the mid-1950s. Since October 2019 the remaining head building has housed the Leipzig City Archive.

The hall represents Leipzig's industrial past and shows how exhibition spaces adapt to serve contemporary needs. Visitors can observe how traditional construction methods remain visible in the exposed structural elements.

The hall is accessible via nearby S-Bahn stations and tram lines that connect to the city center. Visitors should check in advance whether tours or events are scheduled on the day of their visit.

The hall's 1927 sports use came from a deal: the machine-tool manufacturers lent their exhibition hall in winter, and the Sportplatz Leipzig association paid to convert the interior for 8,000 spectators. The architects added an antique-style portico to the plain modern hall, and it opened as the Achilleion on 8 October 1927.