Spanish is the third most widely spoken language in the world after English and Mandarin. Learning Spanish gives you the opportunity to open yourself up to a multitude of people, previously not possible.
As many as 24 countries in the world have a sizeable Spanish speaking population! Learning Spanish exposes you to culture and infinitely more amazing travel experiences ranging from Argentina and Mexico in the Americas to Spain in Europe.
For someone who already speaks English, Spanish is relatively one of the easiest language to learn because of its similarities with English. Learning Spanish also gives you a decent head start in learning other European languages like Italian and French, if you so desire later.