Ruin
A ruin was the physical remains of a once intact building fallen into partial or total disrepair.

By the 23rd century, several planets where the native civilizations had become extinct, were covered with ruins, including M-113, Exo III, the home of the Guardian of Forever, and Camus II. Sometimes, those ruins were studied by archaeologists. ()

Even when a planet was still inhabited by its native species, ruins of previous times could exist. Examples of this were , Sarthong V, Tagus III and Bajor. (; ; )

In the 23rd century, Roger Korby translated medical records from the  ruins. (

In 2369, the ruins of a Rokai provincial capital were discovered on Tartaras V. ()

In approximately 3074, an artifact buried nine meters beneath the ruins at Kesef was uncovered by a Kyrian research team. The artifact was a data storage device which came from the . It was later discovered that artifact 271 was the EMH backup module, a backup copy of The Doctor. ()

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Architecture