Why: Tepoztlán is an ancient town north of Mexico City, on a plateau surrounded by mountains. It only has one main street, but it is the most magical place because it has 600-year-old pyramids dotted on the mountains - apparently, they have perfectly equal sides, down to a millimetre. In Mexico, there is a wonderful juxtaposition between ancient civilisation and modernity. You are constantly reminded of the past but also of the present and the future. So, as well as these pre-conquest pyramids and a 16th-century monastery, there is some brilliant modern architecture. In short, it is a distillation of Mexico's past, present and future with beautiful shapes and pink and orange colours.

I went last year and stayed in a little parador. It was incredibly still and I had the most amazingly vivid dreams. The indians say that it is due to the mineral wealth of the mountains, but I think it might either be because you are high up or because of the contrast between the pollution of Mexico City, the clean air and being so stimulated by the colours.

What's the best thing? Sitting in the town, you can look up to the pyramids on the mountain and take in the old from the new.

My advice: Stay in a local parador. Walk through the streets at dusk. The shapes, the sounds and the colours are so vivid against the presence of the mountains.

How do I get there? Journey Latin America (020-8747 3108) offers return flights with American Airlines to Mexico for £309 plus taxes from October through to the end of November.

• Colour by Judith Miller is published by Marshall at £25. Founder of Miller's Antiques Price Guide, she appears on BBC2's The House Detectives in November.