I visited this WHS in August 2014. Merida was my first stopover point after a long road trip in Portugal. It was very hot and dry so the free entrance (being a national holiday) to the National Museum of Roman Art was a godsend. It houses several Roman remains and above all beautiful mosaic floors. Next I visited the Temple of Diana, the Arch of Trajan, the crypt beneath the floor of the church of Santa Eulailia, the thermal baths and a couple of Roman residences and tombs. The combined ticket now costs 12 euros but it's quite worth it for what you get to see. The main highlights are the Roman Amphitheatre and Theatre but before leaving town I also visited the Roman Circus, the Guadiana bridge and the aqueduct. On the whole I must say that I prefer Tarragona due to the amphitheatre's proximity to the Mediterranean Sea and the superb aqueduct there. Merida's star attraction to me was the National Museum of Roman Art.