In /etc/apache2/sites-enabled/000-default.conf I have the following config:

<VirtualHost *:80>
        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html
</VirtualHost>

However, when I visit localhost, I get the "It works!" page, which is located in /usr/local/apache2/htdocs. (I've verified this by changing the file's contents and refreshing the page.)

Why is Apache serving from /usr/local/apache2/htdocs instead of /var/www/html as specified in the config?