MACELLUM MAGNUM
the market house on the Caelian (Not. Reg. II;
CIL
vi. 1648, 9183) which Nero built and dedicated in 59 A.D. (Cass.
Dio lxii.
18), perhaps on the site of the present church of S. Stefano Rotondo.
It is represented on coins of the period (Cohen, Nero 126-130; BM. Nero
191-197, 335-337) as a circular building of two stories, with a central
tholos or domed structure surrounded by colonnades. This is generally
thought to have been destroyed at some later date and rebuilt at the
end of the fourth century for public use, perhaps again as a market.
1
It was transformed into the church of S. Stefano by Pope Simplicius
(468-482); and restored with various changes by Theodore I (642-649) and
Nicolas V
(1453). Of the building of Nero the only remaining portions
are the travertine foundations, part of the enclosure wall, and eight
pilasters of the outer colonnade, but the fourth century structure was
built on the original foundations and appears to have preserved in general
the form of the original. It consisted of a two-storied circular colonnade,
of twenty-two columns, which supported a domed roof. This was
surrounded by an outer concentric colonnade of thirty-six columns, also
two stories high. Outside of this was an ambulatory 10 metres wide,
divided into eight segments by rows of columns (
JRS 1919, 179). The
alternate segments had no outer wall and therefore resembled open
courts. The original circular building of Nero was enclosed by a rectangular porticus,
2 containing shops, of which remains were perhaps still
to be seen in the sixteenth century (Mon. d.
Lin. i. 503-507 ;
Mitt. 1892,
297-299; HJ 237-238; HCh 474; DAP 2. ix. 412-414;
BC 1914, 358;
Altm. 75-76; LR 355-359).
