Spanish words are stressed on the last syllable

if...

...they end in a consonant, OTHER THAN n or s

 e.g.: Valladolid

          El Escorial

          Santander

       Gibraltar

Spanish words are stressed on the syllable

BEFORE LAST

if...

...they end in n or s

or a VOWEL

e.g.: Granada

      Toledo

              Valdepeñas

If a word breaks either of the

"stress rules"...

...then an accent must be written

to show where the stress goes

e.g.: Germán       José

                             Gijón            kilómetro

                             Cádiz            civilización