Four days in Antigua Guatemala: Spain moved the capital and left the best of it

Start in the square, because everything in Antigua is measured from it. Parque Central is a full city block of trees, benches and concentric paths around a fountain, ringed by the city hall, the old palace of the captains general and the cathedral front, and it is where the town sits in the afternoon. Half an hour on a bench here does more for your sense of the place than any museum.

The cathedral is the clearest lesson in what happened in 1773. The Baroque front came through the earthquake more or less intact and is still white, still ornate, still in use, with a functioning church behind it. Walk around to the side entrance and pay the small fee to get into the rest, and you are in a roofless nave the size of an aircraft hangar, with broken vaults, fallen columns and sky where the ceiling was. The present church occupies about a fifth of what the 1680 building covered.

Then go up. Cerro de la Cruz is the hill at the north end of town, ten to twenty minutes on foot to the base and ten more up the steps, and the view from the cross at the top is the postcard: the entire grid laid out below and the Agua volcano rising directly behind it. Go before the light drops and come down before dark. There are police on the path during opening hours, which there did not always used to be.

Fifth Avenue north of the square is the most photographed street in Guatemala and it is worth walking early, before the tuk tuks and the tripods. The Arco de Santa Catalina spans it: a covered walkway built in the seventeenth century so the cloistered nuns of Santa Catalina could cross from their convent to the school without being seen in the street. The clock tower on top came later, in the 1830s. Stand under it and the Agua volcano lines up down the avenue behind you.

The avenue ends at La Merced, which is the one to see if you only see one. It went up in 1767, and its architect Juan de Dios Estrada had watched the 1751 earthquake and designed accordingly: low, wide, bottom-heavy, with squat columns and thick arches. Seven years later Santa Marta flattened the rest of the city and La Merced stood. The facade is mustard yellow under a dense white filigree of plasterwork, and the ruined monastery behind it contains a fountain so large it fills most of the cloister.

Two blocks east, Las Capuchinas is the best of the convent ruins. Nuns lived enclosed here from 1736 until the earthquake, and the surviving plan is startling: a circular tower of cells around a central courtyard, with a vaulted undercroft below it that nobody has convincingly explained. The gardens are kept and quiet, and the roof terrace gives you the town from a second angle after yesterday's hill.

Take the south-east corner of the grid first, while it is cool. San Francisco el Grande is the busiest of the ruined churches, and not because of the architecture: Hermano Pedro de San José Betancurt is buried here, a seventeenth-century Canarian friar who ran a hospital and a shelter for the destitute in the colonial city and was canonised in 2002 as Guatemala's first saint. People come from all over the country to leave notes at the tomb. The ruined half of the complex and the small museum are worth the ticket.

Two blocks north, Santa Clara is the quiet one. Franciscan nuns founded it in 1715, six of them sent up from Mexico, and the earthquake left one of the most ornate facades in Antigua standing at the back of the site, encrusted with stucco saints and mouldings. In front of it is a large walled garden with the cloister arcades running round it, and on most mornings, almost nobody in it.

Then leave town. Pacaya, an hour and a bit south, is one of the few volcanoes anywhere where an ordinary person can walk up to an active vent in an afternoon. Tours leave Antigua around noon, the climb is straightforward until the last stretch over loose black scree, and you finish standing on cooled lava with heat still coming out of the fissures under it, watching the light go off the plain below. Guides are compulsory inside the park and the foreigner entrance fee is paid on the day.

The last morning belongs to the western edge of the grid, which is where the bus terminal and the market are, so nothing here costs you time you need for the airport. La Recolección is the largest ruin in Antigua and the least visited, a few blocks past the market: a church of 1708 that took damage in 1717 and 1753 before Santa Marta finished it, after which the stone was quarried for other buildings and the shell served in turn as a soap works and a stable. Enormous blocks of the vault lie where they landed. Almost no one else will be there.

Colegio de San Jerónimo, on the way back, had the shortest life of anything in the city: finished in 1757, used as a school and then as the royal customs house, destroyed sixteen years later. What survives is a beautiful square of arcaded ruin around a fountain and a lawn, used now for concerts and dance, with Agua framed neatly from the upper level.

Finish in the market. It is much bigger than it looks from the street, it is where the surrounding villages buy and sell, and it takes a good ten minutes to walk through the produce halls before you reach the comedores. Buy bread at Pan Colonial on the way back to the square, and be at your shuttle pick-up with time in hand, because the road into Guatemala City can be slow.