Grotto replete with mystical designs laid out in glued shell mosaics.

This longship was a gift to commemorate the 1500th anniversary of the Anglo-Saxons arrival in England.

An ancient ossuary in Rouen.

A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

'The Letters of Utrecht' lays out a ribbon of poetry one letter at a time, with no final verse in sight.

This Netherlands museum holds a gloriously mechanical collection of ornate musical automata.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

A large collection of ancient runestones decorates this university courtyard.

Stockholm's deepest subway station is also a stunning ecological wonder.

The scars of a remarkably organized public protest to save 13 elm trees are still visible in this Stockholm park.

The official meeting point for the oddly named governing assembly of ancient Sweden.

This mysterious runestone embedded in a church wall is linked to the medieval cult of Saint Erik.

A small church in Uppsala hides the grave of a renowned 18th-century astronomer.

Legend says this fabled well held part of a mythical Norse tree.

Ancient burial grounds of the wealthy.

The final resting place of the father of modern biological taxonomy.

Legend has it this spring formed at the spot where a medieval Swedish king was killed.

Sweden's "good old days" painstakingly re-created in a model village.

This giant subway sculpture celebrates the fruit that inspired the theory of gravity.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

This homeless brass fox tugs at your heartstrings from the foot of a Stockholm bridge.

Stockholm's tiniest statue is of a small boy looking at the Moon.

A 130-year-old urinal is the oldest of Stockholm and perhaps all of Sweden.

This small museum nestled inside a souvenir shop is dedicated to Sweden's most well-known toy.