The Incan emperor Pachacuti built the amazing Machu Picchu in the 15th century. The Incans abandoned the city shortly after building it, in all likelihood because of a smallpox outbreak, and it remained hidden and unknown for three centuries until 1911 when Hiram Bingham discovered it.

Machu Picchu's architecture is unique and incredibly well-built. The Incan builders hand carved the stones they used for the city's buildings so carefully that even today, 500 years later, not even a thin piece of paper will fit between them. They're still standing not because they're held together with mortar - the Incans didn't use mortar - but because of the superior quality of their stone carving and craftsmanship.

On the morning my husband and I visited Machu Picchu to celebrate his 40th birthday, it rained hard in the morning but luckily stopped as quickly as it started, leaving behind a thin mist that shrouded the ruins in drama and mystery.