Spring had really sprung a couple of days ago. With hardly a cloud in the sky, and a warm day promising, Steph and I headed east some 80 odd miles from our home in north Worcestershire, to visit two properties in Northamptonshire constructed in the late 16th century by Catholic Sir Thomas Tresham, a celebrated recusant who was imprisoned on several occasions for his faith.

First stop, in Rushton, was one of the most peculiar buildings I’ve ever visited but I’d wanted to see for quite some time – I’d seen it on TV in the past year.

The Triangular Lodge – a folly – was completed by 1597, is owned and managed today by English Heritage. This was our first visit to an English Heritage property since we became members at the beginning of the year.

Full of religious symbolism, the Lodge is a perfect triangular building, and there are threes everywhere you look. The sides of the building are exactly 33 feet long, the windows are triangular. There are three floors from basement to upper floor. Each floor has a hexagonal room, with a small room in two of the corners and the stairwell in the third. The roof is a triangular maze.

Constructed of alternate bands of light and dark limestone, the Triangular Lodge is odd – and yet ethereally beautiful – in so many ways. A testament to Tresham’s devotion to the Holy Trinity, it continues to stand in a corner of rural Northamptonshire.

Just 12 miles from Rushton is another Tresham treasure – Lyveden New Bield. At first glance, it appears a desolate ruin, and one imagines what calamity has befallen this impressive building. But it’s not a ruin. Tresham died before it was completed, and there has never been a roof. It is now owned and managed by the National Trust.

Designed as a garden lodge or secret retreat to which he could retire, or even worship as a Catholic in privacy, Lyveden New Bield has all the religious symbolism – and more – that we encountered at the Rushton Triangular Lodge. It is shaped like a perfectly symmetrical Greek cross, each of the four wings of the building mirroring the others. Each of the bow windows has five sections, each five feet wide.

There are no floors but they must have been in place at some time or another since there are wood remnants in the walls where joists would have spanned the building. You enter the building through a very low servants’ entrance (on the south side), into what would have been the basement; there’s a large fireplace and behind, a series of ovens in what must have been the kitchen.

The main entrance, on the north side, is almost six feet or so above ground level. The arches above the entrance and to other internal doors are fully finished and sculpted.

The lodge stands on an open lawn, surrounded by a ditch on all sides, not far from the moat that once surrounded (but on three sides only) a 14th century manor house, now totally demolished and erased from the landscape. But nearby, there are the outlines of what would have been a parterre, and more intriguingly, a Tudor labyrinth. Its existence only came to light in recent years after someone discovered a wartime aerial photograph from the Luftwaffe – presumably on their way to raid Coventry or Birmingham. An old orchard has been replanted with varieties of apple, pear, plum, damson, quince and medlar among others from the National Fruit Collection at Brogdale in Kent. Nearby is the old hall, Lyveden Old Bield, which was Tresham’s home after he moved from the original family home of Rushton Hall.

As a young boy, Tresham went to live with the Throckmorton family of Coughton Court near Alcester in Warwickshire (and only 12 miles from our home) and eventually married one of the daughters. One of their sons was implicated in the 1605 Gunpowder Plot, as were the Throckmorton family.