g. Castellum Aquæ, or reservoir of Alexander Severus.
g*. Aqueduct of the third century.
h h. Exhedra of the Ludus Magnus.
i i i. Great Drain of the Colosseum, to convey the water to the Tiber.
k. The exact spot where the water runs down from the Cœlian into the Colosseum, called a natural spring, but not having the usual bubbling character of a spring.
l. Via di S. Giovanni in Laterano.
m. Via Cœlimontana.
n n n. Orto Botanico. Waste ground at the foot of the Cœlian Hill, planted with trees and shrubs, called the Botanical Garden, but not used as such.
o o. Via del Arco di Constantino. The road between the Cœlian and the Palatine Hill.
p. Podium of the colossal statue of Gordianus, 50 ft. high.