My sister and I took the train from Amsterdam to Brussels on a day trip back in October last year. The train ride was not too bad. It took us 2 hours and 45 minutes to get to Brussels Central Station. There is no need to take the Thalys, because the duration is more or less the same with the regular international train. There are just less stops, when you take the Thalys, but traveling with the high speed train is more expensive and it requires seat reservations. And the Thalys does not stop at Brussels Central Station, although you can always take the subway to get to the Central Station.
Though Belgium is our neighbor, this was my first time visiting Brussels. We could not have picked a worse date for visiting Brussels. The weather was not very good. It was drizzling in Amsterdam. Well, I thought it was not going to be any rain in Brussels though. Haha. Our first stop was the Grand-Place (or Grote Markt in Dutch/Flemish or Market Square in English). Luckily, every street name in Brussels is in French and Dutch/Flemish. At Grand-Place you can find the Tourist Information Center on the ground floor of the Town Hall.
Town Hall (Hôtel de Ville).
King's House (La Maison de Roi) which is the Town Museum now.
House of the Dukes of Brabant (La Maison des Ducs de Brabant).
Guildhalls (from left to right: The Fox, The Horn, and The She-wolf). The Horn (La Cornet) was the Boatmen's House.
Guildhall The Golden Sloop (La Chaloupe d'Or) that belonged to the most powerful guild of tailors since the 16th century.
After visiting the Grand-Place, we left for visiting the (in)famous Manneken Pis. It was a pity he was not dressed, when we were there. However, we could see his 'natural' beauty that way. Haha.
According to one of the legends, the boy had extinguished a fire, thereby saving Brussels from disaster.
We bought a day pass for traveling on the public transport for 4.50 euros and went to take the subway to the Atomium where the closest subway station is Heysel/Heizel.
At the subway station.
The Atomium.
The Atomium was built for the Expo in 1958. It symbolizes an iron crystal, but then 165 billion times larger.
Me and my sister.
Inside the Atomium.
There were escalators, elevators, and stairs connecting the different spheres of the Atomium.
Mont des Arts (or Kunstberg in Dutch): Apart from offering a good view of the Grand-Place, I did not know what to think of it.
Random buildings near the Mont des Arts. 
Musical Instruments Museum. 
Place Royale; that is the name of the square, not the building. I am not sure whether this is part of the Royal Palace.
Le Palais Royal.
Le Palais des Académies
Parc de Bruxelles (Park of Brussels).
View of a rainbow inside the Park of Brussels.
Just a random building.
I think this was the shopping mall Galerie Ravenstein.
Apparently, there was a Made in Korea festival in Brussels. If you take a look at the right upper corner of the picture above, you can see the Korean flag among other flags.
Inside Galerie Ravenstein.
The picture above shows the Lotus: Zone of Zero (2008) that was created by the Korean born, New York based artist Kim Sooja. It consisted of approximately 2000 lotus flower shaped lanterns. And sounds of Gregarian, Tibetan, and Islamic chants could be heard. This work by Kim Sooja is a call for peace, love, and understanding among human beings.
The Cathedral of Saints Michel and Gudule (La cathédrale Saint Michel).
Taking the train back to Amsterdam.
