The town and castle were built on a curiously shaped rocky eminence which commanded the entrance to the valley, leading to the heart of the Island. The town's full name derives from this, but has fallen into disuse.
Cronk with its strategic position became a fortified town at an early date, but the castle is relatively late. It is a development of a much earlier Celtic Peel or Refuge Tower. It was built in 1104 by Sigmund, the first King of an independent Sodor. He pulled down the Peel, and replaced it with a Norman type motte and bailey. He would make it his capital. During the Regency, Cronk was part of the "triangle" usually occupied by the invading power.
During the Great Rebellion Cronk, having been promised Irish help via Harwick and Peel Godred, held out for four months against Oliver Cromwell's forces; but the relief never came so the garrison surrendered on honourable terms, and the castle was blown up. The ruins are now in the care of the Sodor Island Trust.
The town is a busy one but has no big employer. There are instead a large number of small firms all engaged in light electrical industry or instrument making of one form or another. Cronk is a fascinating town, and an ideal centre from which to explore the Island. It has a number of good hotels, of which The Crown of Sodor in Sigmund Street is considered the best.
In the early 1850s, the Sodor and Mainland Railway proposed to build a branch line from here to Peel Godred in order to get support from investors in the area, but ended up reaching neither town. Another failed attempt to build a railway to here was the Cronk and Harwick Railway, but this soon ran out of funds and went no further than Cregwir. Cronk was finally connected to the rest of Sodor by rail when the North Western Railway was built between 1915-16. Since then, the nearby village of Killdane has virtually become a suburb of Cronk. Mr. Kevin Volley was Stationmaster of Cronk Station between 1960 and 1968.
Just to the west is a magnificent viaduct where Gordon once had his dome blown off in 1957. A few miles to the north is a recognised public school and the ruins of Cronk Abbey, both of which are serviced by Abbey Station on the Peel Godred Branch Line.
It was first seen in the Railway Series book Stepney the "Bluebell" Engine where Gordon takes over the train from Duck and Stepney. It later appeared in Enterprising Engines where Flying Scotsman and Donald take over the failed diesels' trains from Henry.
In the television series, it made an appearance in the sixth season episodes, A Friend in Need and Jack Jumps In and in a Jack and the Sodor Construction Company episode, Mud, Glorious Mud, as well as an eighth season learning segment, How Does Emily Get to the Station? and the song, Navigation. It was mentioned in the Jack and the Sodor Construction Company episode, A Happy Day for Percy and the seventeenth season episode, Gordon Runs Dry.
- A siding was added in the eighth season learning segment, "How Does Emily Get to the Station?" and in Jack and the Sodor Construction Company, a car park was added.