One of the finest collections of art in London is not as well known as the National Gallery or the Tate but is a must for any art-lover, together with the fourth, the Courtauld Institute. Admission is free.

The Wallace Collection was amassed by the Marquesses of Hertford and their last successor, Sir Richard Wallace, after whose death it was bequeathed to the nation in 1897. It is still in the original house, Hereford House, kept together, and bears the imprint of the tastes of the various collectors in the family.

It is immensely rich in classical French painting, such as Jean-Honoré Fragonard, Antoine Watteau, François Boucher, Jean-Baptiste Greuze, and many others, including some of their best-known works, such as Fragonard's Girl on a Swing, Poussin's Dance to the Music of Time.

There are great numbers of fine Medieval, Renaissance, and Dutch paintings, and other famous images include Frans Hals's The Laughing Cavalier and Sir Thomas Lawrence's portrait of George IV.

The most surprising aspect is one of the world's best collections of arms and armour: gallery after gallery filled with breastplates, guisarms, bascinets, scimitars, morningstars, and everything else you've ever read of and wondered exactly what they look like. There are complete equipages for both men and horses (and clear proof that medieval folk were not shorter than us), endless sets of eastern armour (Persian, Indian, Japanese), and a Landsknechten sword light enough to be carried by infantry yet which could cut a man in half with one blow, which always gives those who read that pause for thought.

In nearby galleries however are beautiful little gold and enamelled snuff boxes. The rooms are all packed with overpowering furniture tending to the baroque and/or rococo, and clocks everywhere, too many of them ormolu and covered in cherubs, with the thousand variations of the horologer's art they so loved. There's marquetry and Sèvres porcelain wherever you turn, and in the medieval section there are miniatures and ivory carvings of exquisite detail.

The house is on Manchester Square, and was built in the eighteenth century for the Duke of Manchester. It served as Spanish Embassy for a bit, and as French Embassy in 1836-50, but mainly between 1797 and 1897 it was the London home of the four Marquesses of Hertford and then the last Marquess's illegitimate son Sir Richard Wallace. Lady Wallace gave it to the nation and it opened to the public in 1900. The family were phenomenally rich and voracious collectors, especially the 4th Marquess, who is said to have been "notorious for his invincibility in the sale room".

Manchester Square is in the back streets of Marylebone just north of Wigmore Street, and not far from Selfridge's on Oxford Street. Nearest tube: Bond Street, or if coming from another direction, get off at Baker Street and walk south.