This is an excellent day trip from Lisbon, although it does not match the Viator description. You start at Pena Palace, a fascinating combination of 16th-century monastery and 19-century palace, and continue to Sintra for an excellent lunch, with time to tour Sintra Palace on your own.

The drive back along the coast is gorgeous, even in November, with a couple of short sightseeing stops, most notably at Cabo da Roca, westernmost point in Europe.

I would definitely recommend this trip.

This was a well-run, well-guided trip, led by a knowledgeable guide who deftly juggled 4 languages. The first stop was a 1-hour sojourn in Dinant, a town of brick and stone buildings sprawled along the river Meuse. Its main claim to fame is that it was the lifetime home of Adolphe Sax and birthplace of his eponymous instrument, and saxophones are found everywhere.

A journey through the lovely Ardennes, a landscape of forests and fields, takes you to Luxembourg, a city of many high, long bridges, spanning the river and several deep chasms. The low spots are full of buildings and parks, linked by lots of steps and steep roadways. We had only 3 hours there, but we got a very comprehensive walking tour, a chance to explore a few buildings, and 1 hour of free time to prowl. The ruins of the original 10th-century castle that founded Luxembourg are still in evidence, and there's a cathedral with an enormous crypt. Guarding the tombs of the grand dukes are a particularly impressive pair of bronze lions.

Even if you end up spending more on the card than you would have on admissions, it's a bargain. Clutching the card in your hot little hand allows you to bypass the pesky lines at the major museums, and lets you into a lot of the small ones. You also get unlimited transportation on all metro, trams, and buses, saving the hassle of buying individual tickets.

First, the gardens themselves are every bit as fabulous as described. Seemingly limitless beds, not only of tulips, but also daffodils, amaryllis, hyacinths, daisies, and any other flower you can imagine that blooms in the spring. In addition, I was lucky to be there on a day when all the trees were in bloom as well. The gardens really are a "must see".

However, I didn't think the trip itself offered a good value. I have no idea why the company charges more for the 3/4 and full-day tours, as you get exactly the same thing as for the 1/2-day tour. No matter what you pay, you get transportation there, admission, and transportation back. That's it. There was also supposed to be a drive through the tulip fields, but this didn't happen because "the fields were a parking lot". If I want to do this again, I would research public transportation to the gardens and try to go on my own.

Even if you end up spending more on the card than you would have on admissions, it's a bargain. Clutching the card in your hot little hand allows you to bypass the pesky lines at the major museums (particularly the Rijksmuseum), and lets you into a lot of the small ones. You also get unlimited transportation on all trams and buses (and the somewhat limited metro), saving the hassle of buying individual tickets.