As has been noted, this visitor's bureau has brochures on just about any activity within the province both in english and in french. The staff are more than helpful and will readily guide you to the best option that suits your needs. Grayline inhabit part of the building which regrettably seems to give it some official presence/relationship with the bureau but our advice would be to be astute as to what tour, if any, that you decide to do (in terms of value). As advised by another contributor, metro/bus passes can often achieve the desired outcome with greater flexibility than tours such as the hop on-hop off bus.
Located downstairs is a caferteria of sorts and the toilets. And just to finish off with the weird humour of the day - there is are condom vending machines in both the male and female toilets along with a reasonably gross poster in the female. I'm not sure whether this reflects on the behaviour of the tourists or that of the staff in the building - perhaps its all about engendering 'togetherness'.
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