The plaza is really just small. If you aren't into checking out stores and boutiques there, a mere 15 minutes will be enough to cover one end of the plaza to the other.
But, how can you maximize what the plaza has to offer, aside from the Iberian-inspired flooring and colonial buildings?
1. One of the principal buildings in the plaza, the Santa Casa da Misericordia (Holy House of Mercy), houses one repository of sacred arts (really old paintings), objects (Chinese-looking Jesus images), and relics (like the displayed skull of the first bishop of Macao). It can be tricky finding the entrance to it as the front is being occupied by a bank. You have to go through the alley to its right and you'll see the entrance to the impressive museum on the side of the building. There's a minimal fee of 5.00 HKD -- pretty cheap actually! Another reason why you have to visit this place is because its the only building whose second floor can be accessed by tourists - thus, giving you another view of the plaza from the top. I discovered this accidentally in my desperation to stay longer at the plaza and make more sense out of it :)
2. Church of St. Dominic has a free museum. Enter the passage way to its left. This is another way to have another perspective of the streets below as you can go as high as its third floor. Highlights of this place are... of course... more religious objects and sacred arts. It is not as boring as it sounds, so step aside your prejudices and give it a look.
3. Another historically important monument that is largely ignored by ordinary tourists is the Chinese temple of Kuan Tai (Sam Kai Vui Kun). This is just located behind the pink and yellow colonial buildings. It's a small temple, but it has been instrumental in shaping Macao's trajections as a trading town; thus, this is a specified UNESCO-protected monument. This place is a fast reminder that the historic centre isn't all about colonial-era buildings and Western architecture - it is still Chinese.
4. Lastly, why not send your friends some postcards from their beautiful post office main building?
These should be able to keep you busy -- in some meaningful, educational, and productive way -- in Largo do Senado for three hours or more...
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