Oella is a mill town clinging to steep hills and winding streets next to the Patapsco River. Oella Historic District was added to the National Register of Historic Places in 1976. the village can be reached via Oella Avenue, which branches right off Rt 144 after leaving Catonsville and re-enters 144 just before it crosses the river into Ellicott City. Highlights of the village include a row of red brick 19th century workers housing facing the river. The original mill was destroyed by fire, so what exists now is an early 20th-century replacement. Many of the stone buildings date from the early 19th century. Large wood framed houses are perched on the cliffs above the main avenue and can be reached by winding lanes one car wide. Fortunately, there are a few places along the avenue where one can pull off and get a good view of the river and surrounding buildings.