Yew trees feature pretty regularly on walks with my family, as their tough gnarly trunks often provide excellent climbing opportunities for young adventurers. Well-established trees, with their deep twists and hollows, can evoke fantasy and fairytale. The dense canopy casts an eerie light onto the dark branches below, making the perfect setting for den building and imaginative play.

Yews are impressive trees. They are often overshadowed by our beloved English oaks and other large, broadleaf trees but, although small (they grow 10-20m high, whereas an oak can be 40m), they are mighty. Yews are pretty indestructible and have an amazing ability to recover and renew.

They grow slowly, producing dense strong wood that is resistant to fungi that can decay other trees. New shoots from the base can fuse with the main trunk, strengthening it. Even apparent dead wood can produce new shoots. If boughs droop with age and weight and reach the ground they will root and produce a new trunk.

Many ancient yews have huge trunk girths with hollow centres

The central trunk will begin to hollow or split, but will be gradually surrounded by new younger trunks, which can merge to form a wall of sorts. This is why many ancient yews have huge trunk girths with hollow centres, or can appear to be several trees, but are in fact one tree with a shared root system.

I don’t say ancient lightly – they are so well lived that a yew must be 900 years old to be considered ancient. Yews are the oldest trees in Europe, with 10 in the UK believed to predate the 10th century.

The oldest of these, the Fortingall Yew in Scotland, was reportedly 17m in circumference at its peak, and is estimated at between 2,000 and 3,000 years old, with some experts suggesting it could be much older still. It is very hard to date an ancient yew tree, as when they become hollow you cannot count the rings.

Another, the Crowhurst Yew in Surrey, once had a table and chairs placed within the hollow centre, and still has a wonky door fitted in one of the gaps in the trunk to allow access to the ‘room’ inside. No wonder yews have a magical quality.

Yew trees are traditionally found in churchyards, with at least 500 in the UK predating the buildings themselves. They also feature in folklore and mythology, where as well as being symbols of life and resurrection, they are also omens of doom; perhaps because almost all of the yew tree is very poisonous. In fact, the toxin found in yew is extracted and used to treat cancer in modern medicine.

Many notable trees in Gloucestershire

Notable trees locally include the yews bordering the door at St Edwards Church in Stow-on-the-Wold, which have fused with the building itself, becoming decorative pillars appearing to flow from the stone. The monumental hedge at Cirencester Park is the tallest yew hedge in the world.

The 99 yew trees of Painswick Churchyard are also a spectacle, even at a youthful 300 years old. If looking to spark some young imagination, visit Puzzlewood in the Forest of Dean for a magical woodland walk, including yews with amazing root formations. There are many more, so keep an eye out for these modest but fantastic trees.