Ritual site in Newgrange, County Meath (ME019-067003-)

Explorer Tom You reckon you are punctual? Try keeping an appointment for five thousand years. Newgrange is older than Stonehenge, but it still knows how to make an entrance. At the winter solstice, sunrise reaches through a small roofbox above the doorway and lights the chamber at the end of a passage about 19 metres long. Imagine hauling roughly 200,000 tonnes of earth and stone into a mound, then arranging for the sun to make a punctual visit. That little roofbox has better timekeeping than me, and it has never owned a watch. The entrance stone weighs about five tonnes and carries carved spirals; elsewhere, some carvings were placed on faces that would be hidden under the finished structure. That is an extraordinary amount of work for an audience of almost nobody. Twelve standing stones remain from a possible circle of thirty-eight, and the bright quartz front you see today includes a twentieth century reconstruction that archaeologists still debate. The mound is a monument, not an open shortcut into a chamber, so follow the site's visitor arrangements for entry. I will be outside, trying to arrive on time for something for once.

Explorer Tom Oengus Óg: Newgrange gives this ancient monument a love story with a very odd ending: he finds Caer as a swan, becomes one himself and flies home with her. I was ready for a romantic walk; Oengus went straight for wings. Fair play to him.

Explorer Tom Mill House in Rossnaree remembers when a fox took charge of the flour sacks during a power cut. The wheel is still there, looking tired after centuries of grinding. Walk past slowly like you’re inspecting for termites.

Explorer Tom Catholic Church of the Nativity in Rossnaree smells like old books and fresh rain, according to my very reliable nose. The plaster vault inside is fancy enough to make you feel underdressed. Toast it with a cup of tea from your car window.

Explorer Tom You see one mound? Give Knowth another minute to complicate your day. Knowth looks like one enormous grassy mound in the Boyne Valley until its stonework starts giving away the plot. The main monument, built around 3200 BC, holds two separate passages, one entering from the east and one from the west. Around its base stood 127 kerbstones, and excavators found more than 200 carved stones, including art hidden on faces that visitors would not normally have seen. If I could read every carved line, I would still let the builders keep a few secrets. That is quite a private gallery for a place already making a public impression. Centuries later people built a royal residence on top, using the old mound for a new kind of authority. Knowth is part of the Brú na Bóinne heritage complex, and visits are managed through the visitor arrangements there; check current booking and access before going. Study the carved spirals, but leave the ancient builders at least one secret they can keep.

Explorer Tom Moat in Knowth suspects the postman is up to no good and keeps an eye on every delivery. It’s the focal point of the whole cemetery, acting like a proud grandpa at a family reunion. It's free, it's odd, what more do you want?

Explorer Tom Dowth Castle in Dowth has been sitting on that ridge since 1234, looking smug about it. Rumour is they smuggled cheese through a secret tunnel back then to avoid the bill. Stop the car, it’s worth the hazard lights.

Explorer Tom Battlefield near Sheephouse has developed a deep suspicion of the postman, likely due to all the letters never delivered. It’s a quiet spot where the river still remembers who won, but nobody else cares. Have a wander and a wonder.

Explorer Tom Common Lime in County Meath hosted a legendary matchmaking session where two locals finally admitted they liked each other under its branches. It’s seen more heartbreaks than a soap opera. Bring a camera and your most suspicious face.