<svg width="500px" height="500px" viewBox="0 0 500 500">
    <rect x="250" y="250" width="50" height="50" fill="#4bc0c8">
        <animateTransform attributeName="transform" type="rotate" begin="0s" dur="10s" from="0 200 200" to="360 400 400" repeatCount="indefinite" />
    </rect>
</svg>

body {
  background: #f2f2f2;
}