Cartegna

Haven’t been there in years and wasn’t overly impressed with the city. I just went to watch an archeological dig in progress. I did a quick TripAdvisor check and there is the Bateria de Castillitos, and Bateria de Cenizas that look interesting as does the civil war shelters museum. It also lets Calle Mayor and Plaza de Ayuntamiento as places to see.

Assuming you mean Cartagena, I didn't even know there was a flea market. If the Roman ruins means the theatre then there are also other ruins of the Roman forum and you can visit some mosaics under various houses, plus a very tiny bit of the Punic wall remains to see (small, but unique). The Civil War Museum in an old air-raid shelter is worth seeing and quite moving, you go there by lift that also goes to/from the castillo (not Murcia's best castle, but the views are great). The underwater archaeology museum is well-done & interesting even of you don't think it's a topic you would care about, and if you go to the maritime museum you can see the Peral.

Overall, I don't think Cartagena really has any "must sees", apart from the Roman theatre perhaps. It's just an ordinary port city with the usual castle, ruins, museums, architecture, etc that many places have. It's a pleasant city to live in and walk around (the central part anyway), and the food choices are good, but there is no Alhambra or Westminster Abbey to see for instance.

Thanks Nick, you described it better than I. Not overly impressed probably wasn’t the best wording.

The TI didn't want me to go to the flea market as it is outside of the normal tourist zone. It was fun, nothing exciting but puts you right into a working class neighborhood. We had to walk intil we found a taxi. I found it an interesting slice of life with Spaniards and Muslims in the flea market.

We enjoyed being in the city, walking around, dining. Of course, we also visited the antiquities which were presented in a nice way.