By bus from Trieste, Piran
There are some direct buses operating from Trieste (Italy) to Piran and viceversa. These calls at various towns and villages such as Koper and Izola . The journey lasts around 1 hour and half.
I visited Piran as a day trip from Portoroz; so I took a local bus. I suppose the journey between Piran and Portoroz should last around 15 minutes.
Trieste is the usual Italian getaway city from which people reach coastal slovenia. From the bus station opposite the train station there are at least 2 buses a day in each direction. Tickets are 1000 sit.
Trieste to Piran
11.00 - 12.35
17.00 - 18.35
Piran to Trieste
13.25 - 15.00
19.55 - 20.30
You can take a direct bus from Trieste to Piran. The modern coaches are run by SAF and leave seven times a day from within the bus station itself. A ticket costs 4.65 Euros. The return from Piran bus station to Trieste costs only 1,000 SIT. The bus calls at various places – such as Koper and Izola – along the way and Piran is the final stop. The international border crossing takes about 15 minutes and border police walk through the coach first at the Italian and then at the Slovenian checkpoint about 100 m further on. Total journey time about 90 minutes.
From Trieste there are about five buses a day. We paid about 9000 lire single to Piran. The bus stops in Koper, Izola, Portoroz and finally Piran taking about 1hr 40mins. There seems to be a scheduled wait at the border to allow for problems I imagine. On the return journey you need to pay in Slovenian Tolars. Children are cheaper if they are under 1 metre tall. The bus station is on the edge of town and following the coast with the sea on the left takes about five minutes to reach the centre and Trg Tartini.
It is easier to walk around Piran