I went to Brussels twice in the past one year and a half. One time for 24 hours from London and the second time morning to night so I thought I would share my experience. I booked a standard return ticket on Eurostar online and printed the tickets at home. I took the train from London which is about 2 hours.
The train left from Pancras Station in London in the morning. With minutes, I checked in electronically and then quickly went through passport control & security. The whole process didn’t take more than 15 minutes. If I had taken the airplane, I would have to be at least two hours before at the airport for checking in and one hour car journey from the hotel to the airport. Knowing how busy London Heathrow Airport, the process of checking in, going through security & passport control would have taken more than 30 minutes. I admit I enjoyed the experience. I thought it was better than taking the airplane.
This is the highlight of my day trip:
I went to Grand Place which is a famous square in Brussels. If you are a fan of flower plants and bulbs, you will see small booths with a variety of flowers, seeds and bulbs. I also ate Belgian waffles in Maison Dandoy which is considered in Brussels among the best places for Belgian Waffles. You can also take horse carriage from there.
For designer shopping: I suggest Boulevard De Waterloo & Avenue Louise. The two streets are long and are across each other. Many of the famous European designer boutiques are located there such as Hermes, Chanel, Armani, Louis Vuitton, etc.
As for Chocolate, you have to go Grand Sablon. In this area, you will see Godiva, Pierre Marcolini & the famous Witamer Cafe. Whenever I am in Brussels, I eat Dark Chocolate that is good for a month. I am huge fan of dark chocolate so I kind of went WILD. I bought boxes of dark chocolate from Pierre Marcolini. They had many varieties of dark chocolate treats: Dark chocolate with Safron, Dark Chocolate with Early Grey, etc. Some are really strange but delicious combinations. By the way, watch out as some varieties has alcohol ask them before your purchase. I also ate Bouquet of Dark Chocolate covered Strawberries from Godiva and Dark Chocolate Ice cream from Neuhouse. 😛 😛
It was nice experience. I highly recommend it. Since I tried Day Trip from London (morning to night) and 24 hours, I prefer the 24 hrs as I found spending morning to night was tiring.