Strabo Geography 5.3.12

[12] But within-side the chain of mountains, [where these cities are situated,] there is another ridge, leaving a valley between it and Mount Algidus; it is lofty, and extends as far as Mount Albanus. ¹ It is on this ridge that Tusculum is situated, a city which is not wanting in adornment, being entirely surrounded by ornamental plantations and edifices, particularly that part of it which looks towards Rome. For on this side Tusculum presents a fertile hill, well irrigated, and with numerous gentle slopes embellished with majestic palaces. Contiguous are the undulating slopes of Mount Albanus, which are equally fertile and ornamented. Beyond are plains which extend some of them to Rome and its environs, others to the sea; these latter are unhealthy, but the others are salubrious and well cultivated. Next after Albanum is the city Aricia, on the Appian Way. It is 160 stadia from Rome. This place is situated in a hollow, and has a strong citadel. ² Beyond it on one side of the way is Lanuvium, ³ a Roman city on the right of the Via Appia, and from which both the sea and Antium may be viewed. On the other side is the Artemisium, ⁴ which is called Nemus, ⁵ on the left side of the way, leading from Aricia to the temple. ⁶ They say that it is consecrated to Diana Taurica, and certainly the rites performed in this temple are something barbarous and Scythic. They appoint as priest a fugitive who has murdered the preceding priest with his own hand. Apprehensive of an attack upon himself, the priest is always armed with a sword, ready for resistance. The temple is in a grove, and before it is a lake of considerable size. The temple and water are surrounded by abrupt and lofty precipices, so that they seem to be situated in a deep and hollow ravine. The springs by which the lake is filled are visible. One of these is denominated Egeria, after the name of a certain divinity; however, their course on leaving the lake is subterraneous, but they may be observed at some distance, when they rise to the surface of the ground.