And so to the tower, via the medieval treacle mines

It Was night, and the extraordinary thing about our drive along the pitch-black lanes with their twists and turns, frequent junctions and total lack of signposts, was that we were within six miles of a city with a population of 100,000 people.

It was not the only noteworthy thing about the lanes to the south-west of Exeter. Earlier that day my wife and I had tried to find the custodian of the "castle" we were to stay in that night and had stumbled upon the Dunchideock Treacle Mines. We drove up to what I thought to be the house and noticed a metal plate informing us that this was the "registered office of Dunchideock Treacle Mines, AD 1439". The door was answered by an elderly gentleman who confirmed that he was not the custodian of the castle but the proprietor of the treacle mines. Unfortunately he was unable to show visitors the mine for "insurance reasons", but managed to sell me a jar labelled ''Finest Dunchideock Treacle'' for pounds 1.

In due course we reached the castle, more correctly named Haldon Tower or Haldon Belvedere, and shortly found ourselves climbing 73 steps to the flat at the top that was our home for the night. Another 25 steps leads to the roof, and a magnificent view over Devon. To the east was Exeter, the Exe estuary and the coast, and on the other side Dartmoor. Haldon Tower, otherwise known as Lawrence Castle, is a Grade II building built in 1788 by Sir Robert Palk, a Devon landowner and former soldier, in memory of his friend General Stringer Lawrence, founder of what ultimately became the Indian army. At 900 feet above sea level the tower crowns the 12-mile long Haldon Ridge near a spot where, in 1906, Marconi erected an aerial to conduct some early radio experiments. The ridge is characterised by its woods and open heath. In other areas of the hills, notably on the former Mamhead estate on the eastern edge of the ridge, there are dense woodlands that open out to views of the coast and estuary from the other side. Don't miss the Mamhead obelisk, built between 1742-1745 as an aid to shipping.

In 1992 Haldon Forest was the first man-made coniferous forest to be declared a Site of Special Scientific Interest. Since then, much has been done to encourage birds of prey. These include honey buzzards, goshawks, hobbies and peregrine falcons. In addition there are 34 species of butterfly. Other species in the forest include deer, foxes, badgers, dormice, grass snakes, lizards, adders and the rare beech marten.

Two of the prettier villages on the western slopes are Higher Ashton and Doddiscombleigh which contains the Nobody Inn. The latter is less than two miles from Haldon Tower, but I somehow clocked nearly seven miles on the route that took me there.

We never managed to penetrate the treacle mines. When I later phoned Mr Archibald Winckworth, the owner, he said he might consider my request for a tour if I called on 1 April.