Start at the Brussels Ring, at Louise Square (train: South Station). Follow Louise Avenue on the right side to No. 163. Turn right into P.E. Janson Street there. At Tassel House 1, No. 6, you are immediately in front of the 'Manifesto' by Victor Horta (1861-1947), the master of Art Nouveau. This was his debut in 1893 (just 32 years old) in the new style and, regarding the interior design, the first pure Art Nouveau house in the world. This and three other houses by Horta are now on the UNESCO World Heritage List. Then take the next right onto Livorno Street (Art Nouveau: No. 83). Walk to the second intersection with Florence Street (corner building No. 48). Both houses exhibit the simpler, timeless Art Nouveau style of architect Van Rysselberghe. Return to the previous intersection and turn right into Defacqz Street. Here, Art Nouveau offers radiant works of art at Nos. 48 and 50, magnificent houses from 1897 and 1998 by this other master: Paul Hankar. He designed them for well-known Brussels painters. Briefly turn onto Faider Street at the next intersection to Nos. 83 and 85, designed by two more architects. The first was clearly inspired by Horta. Return and follow Defacqz Street again to No. 71. This jewel was built by Paul Hankar for himself, with a sublime façade full of playful details, such as the four painted niches under the cornice. Decipher the animal symbolism in the cycle Morning-Day-Evening-Night. Continue down the street to Chaussée de Charleroi and follow it left to America Street, also on the left. There, to Nos. 23-25: House and Studio 2 by Victor Horta himself. He built it from 1998 to 1901, at the height of his fame. The relatively simple façade hardly reveals the luxurious refinement of the comfortable interior. Perfectionist Horta designed every detail himself. The house (on the UNESCO list) and the bookstore are open daily, except Mondays, from 2 PM to 5:30 PM; www.hortamuseum.be. Follow America Street to the end (AN No. 205) along a series of cozy inns and across A. Leeman Square to Vleurgat Street. Cross it and take the first left onto Van Eyck Street: Crayer Street (No. 34, Van Rysselberghe). You’ll return to Louise Avenue, which you cross at Rondelle and follow a little to the right. The first left is Belle Vue Street, with Nos. 42-44-46 as a colorful and floral AN ensemble. Choose right again, onto the downward-sloping Munster Street (Nos. 30-32) and leave Klooster Street and Dageraad Street on your right. On the right is a park with the Abbey of Ter Kameren. Turn left here into the street and you will arrive at the Ixelles ponds. Turn left onto Klauwaertslaan and move counter-clockwise around the first pond 3. The water area is surrounded by elegant, stylish townhouses, often with Art Nouveau elements. Both in Klauwaertslaan and in Generaal de Gaullelaan on the other side, which you can also follow. You will always reach the memorial for war victims at de Gaullelaan; across from there, take the rising Vilain XIV Street (Nos. 7-9-11). Then immediately right onto Dal Street, with a whole series of façades to the right, showcasing (affordable) Art Nouveau for the ordinary bourgeoisie. At the end sharply left into Meer Street, again rising. No. 6 charmed with its original, geometric glass parts. Once again to the right and back to Louise Avenue, with No. 224 on the right, a final highlight by Victor Horta: the Solvay House 4. Built with an unlimited budget for Armand Solvay, the son of the famous chemist Ernest. The interior (UNESCO list) is an extravagant visual fireworks display of expensive materials and warm colors. Group visits are possible by arrangement.