Traditional transportation to travel around Porto

I received this postcard from Celia of Porto, Portugal. 

It is so interesting to learn that to getting around the city tour by using a tram. 

STCP is the company in charge the local transportation system of Porto.

There are three (3) tram routes in the city center are operating for tourism purposes, time between ~ 0930 to 1930. Ticketing is integrated with the metro and buses.  

Notes to Travelers : The trams and buses run on the 'semi-honor system', where the passengers are expected to buy the ticket from the machine and 'load' it with the number of rides you expect to take and the number of zones (separate tickets are needed if you are going to take two-zone rides and six-zone rides).  

Further reading : 

• Tram in Hong Kong ; 
• Tram in Melbourne and here ;
• Cable Car in San Francisco
• Double Decker Cable Car in Japan