I haven't mentioned it much here, but my younger daughter went on a class trip to Vimy in honour of the centenary of the battle (we call it the Battle of Vimy Ridge, though in other countries it is remembered, if it is remembered at all, as the northern portion of the battle of Arras) and spent ten days touring around France and Belgium.
The trip was good, though she did have some complaints about spending much of the trip partnered with a wet blanket/complainer who did not want to do much and complained about what they did do. (I am certain her parents will consider their money well spent.) So my daughter missed opportunities to see many things because of her. For instance, they had a chance to visit the Sainte Chappelle in Paris before breakfast one day, but the visit came with a catch: you could not go alone. You had to go with your partner. Younger was up for the trip but her partner did not want to get out of bed just to see another church. So they missed out on seeing this: