PREPOSITIONS OF PLACE IN / ON / AT

IN	For an enclosed space(e.g. rooms, towns, continents). For privates cars and taxis	My brother works in a big hotel. The children are in the playground. He went to work in his car.
ON	For surfaces(e.g. rivers, mountains) and lines (e.g. paths, coasts, roads) For public transport (e.g. planes, trains, buses, boats)	We´ve got a villa on the Mediterranean coast. We had a lovely holiday on the River Thames. She got a job on a ship. I don´t like traveling on buses.
AT	For a particular point, or building. With home and work. To say where people study	We met at the station. Wait at the reception desk. They´re at work. He´s working at home. He´s a pupil at park school. My daughter is at university.