Enable the rewrite module in apache2: a2enmod rewrite
Allow that module to run: edit /etc/apache2/sites-available/default, changing AllowOverride None to AllowOverride All as suggested at StackOverflow
Edit the laraval public/.htaccess file, change the RewriteBase line to contain the portion of the path required to visit the base of the Laraval site, after http://localhost. This comes into play when you have installed Laraval at some location other than the base of your web server.