Cost Of Living

Hi Folks

A few questions regard my first trip to Tenerife

Whats the cost of living like in Tenerife, is it expensive being a tourist destination ? How much should a taxi cost me from the airport to Los Christianos ?

Is Tenerife a safe place to be for a person alone at night (male advancing in years lol) ?

Is it best to take cash or can you readily get cash from the ATM's ?

Are there any places that you should keep well away from ?

Are there any things that are a must do whilst there ?

Thanks

Pat