This junction was in Troon, just east of the harbour. The lines from Barassie Junction, to the north east, and Troon Junction, to the south east, met before running west into the harbour to serve its west side and eastern breakwater. The curve to the north east was the rebuilt line of the Kilmarnock and Troon Railway.
The juncion opened in 1892 with the newer alignment from Troon Junction. There was a weighing station to the south of the junction.
On the line to Barassie Junction there was a yard of around 8 looped sidings, the Templehill Junction being at its western end. A small gas works was at the eastern end, north side.
A goods yard, Templehill Depot, was south east of the junction, the sidings approached from the west.
To the west, between the harbour lines and breakwater line, was Troon Shed. North of the line was a large railway cottage.
Just west of the junction and Troon Shed was Breakwater Crossing Signal Box, which controlled the level crossing, a road crossing over the harbour lines to reach the eastern breakwater.
The site of the original Kilmarnock and Troon Railway Troon [1st] station lay to the west of Templehill Junction and the level crossing.
In Troon Harbour were lines serving quaysides, staiths, a sawmill and the Ailsa Shipbuilding Yard.
The junction closed in 1966, the curve to Troon Junction having closed. The harbour lines and approach from Barassie Junction remained open until 1973.