The National Gallery of Canada ('Maman' Spider & Rideau Chapel) & Notre-Dame Basilica

At the northern end of Sussex Drive overlooking the Ottawa River sit two of Canada's greatest architectural treasures directly across the street from one another: architect Moshe Safdie's pink-granite-and-glass National Gallery of Canada and the silver twin spires of the 1846 Notre-Dame Cathedral Basilica.

1. The National Gallery of Canada (380 Sussex Drive, Free Thursday Evenings)

Before you even step through the doors, walk onto the granite plaza to stand directly underneath the eight towering bronze legs of Maman (1999), French-American sculptor Louise Bourgeois's landmark 9.2-metre-tall (30-foot) bronze spider carrying a sac of 32 white marble eggs beneath her abdomen. Inside, walk up the monumental pink-granite Colonnade ramp into the 43-metre-high glass prism of the Great Hall and explore three highlights:

• The Reconstructed 1888 Rideau Street Convent Chapel (Level 1, Hidden Inside the Gallery): when an 1888 convent on Rideau Street was demolished in 1972, craftsmen dismantled its extraordinary wooden fan-vaulted Neo-Gothic interior chapel in 1,123 numbered pieces and rebuilt it intact inside the National Gallery, where a 40-voice sound installation of Janet Cardiff's Forty-Part Motet plays continuously through 40 speakers arranged in an oval.
• The Indigenous & Canadian Galleries (Group of Seven, Tom Thomson & Inuit Art): stand before Tom Thomson's 1917 icon The Jack Pine, Lawren Harris's Arctic icebergs, Emily Carr's forests and Kenojuak Ashevak's Inuit prints.
• European & Contemporary Masterpieces: features works by Monet, Van Gogh (Iris), Klimt, Cézanne, Rembrandt, Warhol and Bernini around a serene indoor Sunken Water Court.

2. Notre-Dame Cathedral Basilica (Across the Street, Free Entry)

Directly opposite the giant spider on Sussex Drive rise the gleaming tin-clad twin spires of Notre-Dame Cathedral Basilica (built 1841 to 1846), the oldest and largest standing church in Ottawa. Do not be fooled by its sober grey limestone exterior: step through the wooden doors (free admission outside Mass times) to see a Victorian Neo-Gothic interior painted in brilliant royal blue and 22-carat gold leaf, crowned by a midnight-blue ceiling of thousands of gold stars and 200 carved wooden statues by sculptor Philippe Hébert.