I used to take my son with me all over Europe during the holidays, best bit was seeing the Apes in Gibralter…But as has been said, it did get a tad expensive…But it was very enjoyable for us both.
Smc
Bilgepump:
My son (6) out with me for half the week. Four drops in London and Surrey - now he thinks he knows everything about the job. Was pretty quiet till his Nintendo batteries went flat (he forgot to bring the charger). Then he decided to take over as tour guide. Every speed sign - “How fast are we going?”, Every bridge height and weight limit the same - “Will we get in there?”haha sounds JUST like mine, same age
my wee boy is 2 on thursday and loves to come in the truck with me and his mummy
u can get a hi viz vest for kids at coop this week cheaply…I used to go out with my grandad when i was younger and can remember going in ICI and having to kneel down in the footwell to get into the place 
…I was about 10-12 at the time…what fun that was.