Q: Is it free for a couple of nights? Is it safe?
A: I assume you are talking about the VIA rail station. No there is a few for parking. They do have extended lots but to find out the exact prices you would have to go to the ottawa VIA rail website or call the train station to find out the exact pricing for the time periods you will be parking there. As for safe I would think it would be as the train station is always busy. But with any public parking you are taking some what of a risk