Migrant birds sometimes shelter among the bushes, which also harbor naturalized stick insects.
Follow the track eastwards from the gardens, with a pool visible through trees to the right, and turn right just after the Abbey building.
Bear right off the concrete track and on to a broad path through bracken.
There is a better view now of the pool to the right, and another sheet of water appears to the left. They are both worth exploring. The smaller Abbey Pool on the right, which is sometimes only half full of water and has a muddy shoreline, is good for migrant wading birds and has attracted some notable rarities.
The other lake is called the Great Pool. A path off the main track allows a closer view across the reed-beds and the open water. Again this is a place for vagrant birds - a glossy ibis (from Asia) once took up residence on the shore and a Parula warbler (from America), a first for Britain, was discovered among the willow scrub. Even some of the ducks are not what they seem, being the descendants of an American black duck which came to stay and mated with a local mallard.
Bear left, around the foot of the Great Pool, then turn right, (east), before turning left, (north), past some greenhouses.
Alternatively detour to look at the beautiful white sands of Pentle Bay and the scatter of islands beyond. The dunes are attractive, backed by marram and with some patches of exotic garden escapes, notably agapanthus from South Africa.
The path continues northwards, past greenhouses and some tall hedges. These are planted to protect bulbfields from strong winds and did their job well until January 1987, when four days of heavy frost, unprecedented in the island's history, killed off many of the coprosmas and pittosporums. It will take many years to make good the damage.
The Monterey pines proved to be more hardy and there are some fine gnarled specimens alongside the path as it passes little stone-walled fields and approaches Borough Farm. There are also some sycamores, often damned as an alien species but one of the birdwatcher's favorite trees because plagues of aphids usually cover the leaves, providing food for migrant warblers.
Continue along the path, there is a 16th-century blockhouse, (coastal defense), on a knoll or tor to the right. Passing this, the path descends to meet a concrete track, at which turn right, past a little terrace of cottages, and on into the little settlement of Old Grimsby, (the word comes from the Norwegian Grimsea meaning inlet, not from any direct connection with the more famous fishing port). Turn right at a the T junction. A pretty section of coast lies to the right, backed by tamarisk, (a Mediterranean shrub), and other exotics. The beach is private but the views, across to Tean and St Martin's, are excellent and free.
At another junction turn left, (signed 'Footpath to Gimble Porth, Piper's Hole and Castles'), up a path and over a stile, then past a knoll to the right and down to Gimble Porth. This is a pretty bay with sand, pebbles and rocks, ideal for beachcombing and a good place for finding shells. Again, there are fine views of the islands; in the foreground is Northwethel, then St Helen's, then Round Island with its lighthouse.
The path continues northwest, with pasture and woodland to the left and the bay to the right, then climbs steeply to another knoll or tor. This is a wonderful place to stop for a few minutes; the granite boulders make a good seat. On a September afternoon the colors can be dazzlingly pure - blue sea, blue sky, pink and dove-grey rocks, orange Xanthoria and Caloplaca lichens and mauve heather.
From this point there are several options available depending on the time. An exploration of the northern cliffs can be rewarding, as can be a visit to the castle ruins, (one from the days of King Charles I, the other, more intact, from the days of Cromwell). However far you continue, the path back is down the central spine of the island. This provides an opportunity to take a closer look at the strange wind battered heathland, composed of ling and bell heather.
Heading south-east, the broad sandy path begins to descend, past some low patches of western gorse, and is funneled into a walled 'drovers' path' beside attractive little fields (with tall hedges again) and on to the road into New Grimsby. The route heads south with the road, past the quay and cobbled slipway. Bryher lies just across the water and this is the embarkation point. Boats from St Mary's sometimes have to put down their passengers here too, if conditions are difficult at Carn Near.
Just south of New Grimsby, pass Abbey Farm, then the north-western end of the Great Pool, which looks quite different from this side of the island.
Follow the track that runs around the south-western shore of the Great Pool from Abbey Farm to Tresco Abbey. At first, the waterside is lined by reeds and rushes. Scan the open water for wildfowl: blue-winged teal have been seen here among the commoner species. It is possible to walk along a track to a small hide on the shoreline. Towards the abbey, woodland begins to obscure views of the Great Pool. Abbey Wood is an excellent area for migrant warblers and flycatchers in autumn. If you fail to see a rarity don't feel too disappointed - only a handful arrive each year and if there have been no strong gales it will mean they may all have found their way to their proper wintering grounds.