Edinburgh is an extremely accessible city with some lovely architecture, tourist attractions and shopping facilities. It makes it a very popular holiday destination.
If you decide to fly, then once you have landed at Edinburgh Airport getting to the city centre is fairly easy. The airport is situated about eight miles from the city centre and there is a shuttle bus that leaves from the terminal every 10 minutes that takes you right to the heart of the city. There are two services, so depending on your arrival time will depend on which company and route you will take, but both have the same destination. Both services are reasonably priced.
Getting to Edinburgh by ferry is not so straightforward, if travelling from Ireland the ferry from Belfast will likely come into port at Stranraer or Troon and then an additional journey via bus or train is needed to get into Edinburgh. Buses run into the city from all over the country, and there is also the option of coach travel with companies such as National Express who operate from all over the UK.
Travelling from England or Wales is far more straightforward with a choice of options available. All the train routes into Edinburgh run into Waverley Station, which is off Princes Street right in the centre of the city. Of course another option is to drive, with plenty of car parking options it is a good choice, but congestion is always an issue in a major city and needs to be taken into consideration.