Two churches in Brussels. Brussels Cathedral has no online ticket listed; Notre-Dame de la Chapelle has no online ticket listed. The table and the two notes below put them side by side; the full pages have what to see, the ticket and the timing for each.
The cathedral stands on a slope between the lower and upper towns, five minutes from the central station, and entry to the nave is free. Two paid extras are worth considering: the archaeological crypt under the west end, which shows the foundations of the Romanesque church that stood here before, and the treasury. Both are inexpensive and neither takes long. Guided walks of central Brussels pass the front on the way between the grand square and the royal quarter, and comic-strip and art nouveau tours ignore it entirely, which is a reasonable choice if that is your interest.
The Church of Notre-Dame de la Chapelle stands on the edge of the Marolles district in central Brussels, Belgium, a short walk from the Grand Place, the Sablon and the Brussels Central Station, and entry is free. It is one of the oldest churches in Brussels and is known as the burial place of the painter Pieter Bruegel the Elder, who lived in the Marolles district.